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Help! Headlight motor keeps running

John Robinson

Gone but not forgotten
Joined
May 3, 2005
Messages
1,555
Location
Muncie, Indiana
Corvette
1993 Polo Green Coupe
When I turn the headlights on or off the right side keeps running for maybe 5 seconds. I tried to rotate it manually but it just turns freely and then suddenly the door flops open. When I do use the switch to rotate the headlight it does go into position on its own. The flop only occurs when I try to hand adjust. I did try to find information for this in my FSM but was not able to find a chart for this situation. I am wondering if the three nylon pieces could cause this or is it the gears not meshing.
 
When I turn the headlights on or off the right side keeps running for maybe 5 seconds. I tried to rotate it manually but it just turns freely and then suddenly the door flops open. When I do use the switch to rotate the headlight it does go into position on its own. The flop only occurs when I try to hand adjust. I did try to find information for this in my FSM but was not able to find a chart for this situation. I am wondering if the three nylon pieces could cause this or is it the gears not meshing.

John: FWIW: I have/had the same issue. My mechanic and I have continued to work on this issue. The FSM doesn't seem to directly address this specific issue or at least I don't read it that way. However, in reflecting on the mercury limit switches possibly being out of position (I believe that they are the functioning elements that actually open the ground to stop the motors from running) I had the head light assemblies removed from the car to access the cover plates on the base of the "motors" to assess the expected failure/position error of the switches.

Removing the actuating gear cover to remove the nylon drive gear we found fine shavings from the nylon gear face. (No I never though of this old trouble/problem before this effort to look at the mercury switches). In reviewing my situation it seems that this is a common result when the three "bushings" fail and allow the nylon gear to slowly eat its self to death. Replacement is a three (3) nylon bushing set ($5+/-) and either a nylon drive gear ($23+/-) (?) or a brass drive gear ($60+/-). The decision was fairly straight forward for me, 19 years of service life on the nylon gear. Nylon costs 30%+/- of the brass gear. The "bushings" are self sacrificing over time so they WILL HAVE TO BE REPLACED any way so replacement with near OEM (that is nylon) components was my solution. Labor costs are the same for changing nylon bushing with a nylon gear or a brass gear. I will let you know if this fixes my problem.

A final note GM Junkie has always counseled that these machines are reliable and that when there is a mechanical functional casualty don't go for the exotic issue like "mercury switches" look for the simple common solutions FIRST. While this has taken me and my mechanic (kudos to him) nearly a day to sort through this process the actual entire repair will only take about an hour if you don't run into other problems. Zip Corvette has a tech article explaining the process and they also sell the necessary parts.

Hope this helps
 
Mercury switch adjustment ?? 84-87. Different headlite door actuator drive.

The yr models that you guys have listed use a control module, different than the earlier models that used relays and limit switches.

Your problem is in all likelihood the delron bushings that are designed to be wear parts so that the gear drive does not have to absorb the shock of sudden high torque starts and stops. The 3 bushings act as dampners, and roll with the gear rotation. They wear out.

Search the threads here. There have been MANY creative replacement solutions. The same size dowels can be bought and cut to size for pennies...and leaving you with a lifetime supply of bushings.
Buy the gear set if you just want to have it "just in case" but its probably not necessary. BTW...installing brass gears forces the stress onto the worn gear or other parts that are NOT so easily replaced....so consider that before assuming that brass fixes it forever. It may well fix the gear wear, but it will cause something else to fail. Gears are easy and if you got 19 yrs this time...new nylon gears with fresh grease should go at least 1/2 that long giving you 10 yrs of service.
 
I vote nylon bushings. They turn to dust. You will find instructions on the net. Instructions came with the set I purchased from MAW. A little time consuming to replace, but they work like new again. The nylon gears had no signs of wear or damage. I had to replace one of the gear gaskets. I made my own replacement, but they are available on the net. Just a little harder to find.
 
Thanks for the advice. To update you all I removed the motor and the cover but did not go any further because there was'nt any nylon dust or chips. The inside of the cover was operating room clean. There must be a limit switch somewere but I can't find it. I think I will not worry about it anymore since night driving is fast coming to an end with my night vision going bad.
 
An excellent pictorial instructional, from Oz. I seem to remember, that I couldn't see the remains of the bushes until I removed the gear. I removed the worm drive, for access, as one side doesn't pull out easily. After learning on the first, I found others to be relatively simple......Roger.
 
Ok so when I have the cover off how do I get that plastic gear off. I assume the plastic buttons are under it. I am real nervous about prying on a 19 year old plastic gear. If I brake it I am done. I have a 1/2" plastic dowel rod I can make buttons from but I sure don't have any way to make a gear. My golden years of retirement have come down to eating & Medicines and letting both car repairs go unless they just wont run. I am not looking for sympathy just P------ about what the economy has done to us folks on fixed income. When I retired I was given the song and dance that I would have medical, Life, Hearing Eyes all would be covered. Then the company took them away saying I did not have a contract for those things. Well I now have to provide my own insurance. Then they declared bankrupcy and my savings went to .35 cents on the dollar from $55.00. Good bye nest egg. I simply refuse to give up my Corvette it is the only thing I still can believe in and enjoy. It may be athe last of the American dream I can hold onto. So now that I have gotton that off my chest back to deciding which liar I should support for president.:chuckle
 
Well, that was embarrassing.

But, one of the many great things at CAC is the gracious assistance offered by others when one (me) goes off track. My mechanic (a good guy but not really a corvette tech) was the one who mentioned the mercury switches. Not his fault (mine actually) but he has only worked on older Vettes C2s, C3s, and crossfire C4s.. Probably why the FSM didn't make sense to me. Still very much appreciate the counsel and guidance from Boomdriver, Vetteoz, ad Tedc, thank you.

John, I know what you mean, but my blood pressure won't allow me to think or discuss the condition of the Republic today.

However, I scanned the FSM to see if they talk about removing the cover plate and drive gear to replace the bushings. I can't find anything in Section 8(?) or at least I don't see it (might be an age thingy). Perhaps this was a repairable component that the General didn't want owners/operators to work on(?). When the parts get here (hopefully tomorrow) I will see how it goes and let you know.

Muncie, very nice city and community. Used to visit the Westinghouse/ABB plant on the south side. Looks like there is still something (?) going on out there. Google image shows some activity but it appears to be a noon view on Feb. 26, 2012.
 
As I endeavoured to explain. The gear wheel did not pull out, I therefore removed the worm drive, after taking off the cover, which allows the gear wheel to slide out. When reassembling, the tricky part is holding the brushes apart. For this I used two paper clips, bent to suit. This apparently applies to one side only.I cant recall which. Some people get around this by filing the gear wheel.I decided not to do this. I think someone will chime in on that. I can relate to your retirement predicament, in as much as, my life savings were lost by the firm of Smith Barney, who continually assured me that their investment strategy would come right. This leaves me with a ridiculously small pension and no medical coverage at all. Still we have a Corvette and the CAC......Roger...:w
 
Well, that was embarrassing.

But, one of the many great things at CAC is the gracious assistance offered by others when one (me) goes off track. My mechanic (a good guy but not really a corvette tech) was the one who mentioned the mercury switches. Not his fault (mine actually) but he has only worked on older Vettes C2s, C3s, and crossfire C4s.. Probably why the FSM didn't make sense to me. Still very much appreciate the counsel and guidance from Boomdriver, Vetteoz, ad Tedc, thank you.

John, I know what you mean, but my blood pressure won't allow me to think or discuss the condition of the Republic today.

However, I scanned the FSM to see if they talk about removing the cover plate and drive gear to replace the bushings. I can't find anything in Section 8(?) or at least I don't see it (might be an age thingy). Perhaps this was a repairable component that the General didn't want owners/operators to work on(?). When the parts get here (hopefully tomorrow) I will see how it goes and let you know.

Muncie, very nice city and community. Used to visit the Westinghouse/ABB plant on the south side. Looks like there is still something (?) going on out there. Google image shows some activity but it appears to be a noon view on Feb. 26, 2012.

What a small world it is. My father was the site engineer for Westinghouse who built that plant. It was a very unique facility and in fact he had several patents for some of his ideas with that building. After many years of standing as a warehouse a company called Progressive Rail bought it. They are a division of Caterpillar that makes train engines. The building was well suited for them with it having a rail line inside the main aisle and the fact that the floor will hold a million pounds and the overhead crains can lift that much. How long ago was it that you were there?
 
Roger:

Smith Barney as an institution and all that I knew at the Washington D.C. & Bethesda Md. offices should be taken and thrown in prison (actually a pool of liquedfied bovine waste would be better). I had two accounts with them in the eighties/nineties. I got scared when my account executive never contacted me or returned my calls but four to six others were calling me every two hours about the NEED to get in on their latest "deal". They weren't large accounts (never had time to transfer anything in because of all the phone calls) but when I closed them they said that I owed them money(?). On non-margin accounts with no fees???. They took everything (thankfully it was not a lot). Used to have a different "broker" call every few months to seek restitution for a bout the next five years, I think.
Sleaze balls, dirt bags, scum buckets: Smith Barney be thy name.

But in the end we are lucky to still have our Vettes. There is something sublimely erotic/sensual in driving with the top off on back roads through the Shenandoah Valley in late spring. No aches, no pain, vision good, the air is clean and fresh. The only issue is getting in and more troubling out of the C4.

Regardless, thanks to the picture tutorial I can now follow what the mechanic is chatting about.

John:

A very small world, I can't believe the places in this world where I have run into folks I knew in high school/college and other places in the past.

Yes, the Westinghouse Muncie transformer plant was a very unique facility. For a long time it was considered a national security asset. I had an opportunity to visit almost all of the Large Power Transformer manufacturing plants and repair facilities in the U.S. and Canada. There were physically larger facilities, one or two newer ones etc. but nothing like the Muncie facility. It was the lowest cost per KW manufacturing facility in the world. After purchasing the GE Large Power Transformer (LPT) business they were for a brief period the premier manufacturing site for the unique LPT product. I think I visited the plant in for the last time between 90-93. If I could find my diaries I could tell you the date, time, and personalities I met with over the two days I was there.

Interesting to note that what brought Westinghouse down was another mortgage disaster that the Corporate finance guy got suckered into while the Chairman of the Board and CEO was to busy raising Lamas on his estate outside of Pittsburgh. (HMMmmm, he should have gone to jail as well as his finance guy, and perhaps the entire Board of Directors). After ASEA Brown Boveri (ABB) bought the business from Westinghouse I suppose that they couldn't justify the facility since they only professed to be a world supplier but really at the time they only were concerned with Norther Europe and the U.S. Market. The first ABB CEO of the business lost his job over his opposition to the liquidation of the plant. He had vision. The third thing he bought when he was transferred to the U.S. was to purchase a Corvette. (My kind of guy.) I think he is still here in the U.S. someplace in Arizona from California.

Sorry to go off topic. My parts did not arrive yesterday. So will see if they come tomorrow. I will get my mechanic guy back and I will note exactly how he uses the picture tutorial's insight into doing the job of changing the "bushings, etc. if it will help.

Charles
 
Hi Charles, if you are doing both headlamp motors, you will find that, whilst they are the same motor, they are sided. One of them (I cant remember which), doesn't want the gear wheel to disengage from the worm drive, simply by pulling it off, after removing the cover. I managed to do that one first. I therefore removed the knob and the other cover, which exposed the shaft and, pulled it out. The gear wheel was then free. Some people choose to file the gear wheel. My way was more tricky as, when replacing the shaft, I needed to hold the bushes apart, for which I utilised two paper clips, bent to suit. This negated the need to file the gear wheel. It sounds more complicated in writing, than it actually is......Glad to hear your brush with smith barney wasn't too bad, mine cost me $300,000+. Ah, the cost of living !......Roger.
 
Roger:

Smith Barney as an institution and all that I knew at the Washington D.C. & Bethesda Md. offices should be taken and thrown in prison (actually a pool of liquedfied bovine waste would be better). I had two accounts with them in the eighties/nineties. I got scared when my account executive never contacted me or returned my calls but four to six others were calling me every two hours about the NEED to get in on their latest "deal". They weren't large accounts (never had time to transfer anything in because of all the phone calls) but when I closed them they said that I owed them money(?). On non-margin accounts with no fees???. They took everything (thankfully it was not a lot). Used to have a different "broker" call every few months to seek restitution for a bout the next five years, I think.
Sleaze balls, dirt bags, scum buckets: Smith Barney be thy name.

But in the end we are lucky to still have our Vettes. There is something sublimely erotic/sensual in driving with the top off on back roads through the Shenandoah Valley in late spring. No aches, no pain, vision good, the air is clean and fresh. The only issue is getting in and more troubling out of the C4.

Regardless, thanks to the picture tutorial I can now follow what the mechanic is chatting about.

John:

A very small world, I can't believe the places in this world where I have run into folks I knew in high school/college and other places in the past.

Yes, the Westinghouse Muncie transformer plant was a very unique facility. For a long time it was considered a national security asset. I had an opportunity to visit almost all of the Large Power Transformer manufacturing plants and repair facilities in the U.S. and Canada. There were physically larger facilities, one or two newer ones etc. but nothing like the Muncie facility. It was the lowest cost per KW manufacturing facility in the world. After purchasing the GE Large Power Transformer (LPT) business they were for a brief period the premier manufacturing site for the unique LPT product. I think I visited the plant in for the last time between 90-93. If I could find my diaries I could tell you the date, time, and personalities I met with over the two days I was there.

Interesting to note that what brought Westinghouse down was another mortgage disaster that the Corporate finance guy got suckered into while the Chairman of the Board and CEO was to busy raising Lamas on his estate outside of Pittsburgh. (HMMmmm, he should have gone to jail as well as his finance guy, and perhaps the entire Board of Directors). After ASEA Brown Boveri (ABB) bought the business from Westinghouse I suppose that they couldn't justify the facility since they only professed to be a world supplier but really at the time they only were concerned with Norther Europe and the U.S. Market. The first ABB CEO of the business lost his job over his opposition to the liquidation of the plant. He had vision. The third thing he bought when he was transferred to the U.S. was to purchase a Corvette. (My kind of guy.) I think he is still here in the U.S. someplace in Arizona from California.

Sorry to go off topic. My parts did not arrive yesterday. So will see if they come tomorrow. I will get my mechanic guy back and I will note exactly how he uses the picture tutorial's insight into doing the job of changing the "bushings, etc. if it will help.

Charles

After building the plant my dad was assigned as the facility engineer with the responsibility of selecting the machinery and the layout for the building. He was recognized by

Fortune Magazine when it was built and flown to an awards banquet in New York were it was chosen as one of the top ten facility's in the world. When he retired he went to work for ASEA as a consultant and mentor for there engineeers at the new plant they were building in Waukasha, WI. In 1960 he bought a Dodge dart and put 60K on it in 8 months driving from Sharon Pa to Muncie sometimes as many as 4 round trips a week. When he got rid of the Dodge he bought a 1960 Corvette that he and I put 250K on before he died. Look forward to what you find out with your headlights.
 
Hi Charles, if you are doing both headlamp motors, you will find that, whilst they are the same motor, they are sided. One of them (I cant remember which), doesn't want the gear wheel to disengage from the worm drive, simply by pulling it off, after removing the cover. Roger.

Yes, you are correct. I ended up working on the difficult side first which I remember being the passenger side. The other side was very easy in comparison. I loosened up the motor just a little to allow worm gear to clear the ridge on the outer gear. It is this ridge that causes the extra work depending if it is on the inside or outside of the motor worm gear.
 
Roger:

YIKES!!!!! I didn't lose anything like that. I am not real smart (clearly demonstrated early in this thread) but when I open accounts to start moving stuff and I am being overwhelmed by "brokers" selling stuff and "MY" broker isn't returning my calls I simply just got scared.

I don't know if I did the right thing. Some days my bride says I am worth more passed and on others I am worth more polluting the environment. Really not sure what standard she is using as a reference (kinda worrisome when I ponder the nuances). But, there must be something there, she found the 93 and encouraged me to get it after I beat my "c" event. My doctor says it is amazing, given how fast the eruption was and the stage that I reached before they could operate, that I am still here.

I digress, I really appreciate the heads up on the gear removal thingy. I chatted with my mechanic and he indicated that his research with the nearest GMC Certified Corvette mechanic (like 60+ miles away) tried to describe the issues it over the phone. Your explanation made much more sense to him. So when the parts get here (Zip must have sent them by Ox Cart) we will be on it! Thank you so much.

Thanks to everyone as well for all the assistance.

The adventure continues and I am sure that either John or I will have positive outcomes shortly..

Charles
 
John

OK, FWIW black2 is fixed:beer.

Zip provided the parts and also provided detailedinstructions on their web page.

However, we succeeded because Boomdrive providedcritical input which allows us (me and "the" mechanic) to reorientour perspective and thinking. Vetteoz provided additional critical visualreferences which also proved crucial in confirming where we were and what wewere looking at (the Zip images were a wee bit small for us to see as clearlyas we really old geezers would have preferred late at night) TedC offeredgeneral comments and observations which provided very important guidance at keymoments when we were hesitant to continue. Roger's insights from his experienceand technical solutions to the challenges he encountered were also very helpfulparticularly in working on the Passenger side assembly and working around theproblem. .

We did the Driver's side first and found that theactual work time was a little less than an hour. We spent more time reading thedirections and comments and looking at pictures than working on the assembly. Istrongly recommend doing the Drivers side first since that is really straightforward and resolves all the uncertainties of locating things and figuring outhow they disassemble and reassemble.

We then did the Passenger side second. As has been noted thatis the more difficult side to complete. The gasket that fails IS the passengerside. One should order replacement gaskets since they are NOT in the kit thatZip sells. As TedC advised loosening the motor on the Passenger assembly doesassist the work process and allows the worm gear to offer less restriction onthe removal and reassembly of the bushings/gear wheel. GREAT patience isrequired when working on the Passenger side assembly because of the"ridge" in the gear well. When all of the stars are aligned itslips together very easily; but, until that happens it may try your soul. Itreally can't be forced and it just seems to fiddle with one's sanity until itjust slips together.

The nylon gears on both units did not look as ifthey had experienced any wear. We could have used them again but we replacedthem anyway out of an abundance of caution (and we had the parts) but the oldgears have now been cleaned and except for a little yellow age color look asgood as the new ones. The torque bushings were MIA and all that remained in mycar was a little porridge consisting of old lithium white grease and very veryfinely ground nylon.

In the end you only really need the torquebushings. But from my perspective I would replace the gears and use new gasketsfor a complete refurbishment of this function. It is also interesting to notethat the Passenger assembly only took an hour and ten minutes +/- on the bench even with thedifficulties noted above. The units run flawlessly.

Hope this helps John and again thank you to everyone for the comments, assistance, and encouragement.

CAC members are CHAMPIONS
:happyanim:!!!!

Charles
 
Glad to hear that you made it though the rebuild...first time is always stressful. Once done, its now childs play.

Enjoy the springtime with some headlites that go up & down !
 
OK as soon as I suck up some courage I will tackle the passenger side only since the other side is working OK. I am from the old school if it ain't broke don't fix it. I am still a little fuzzy on how to remove the gear. If i understand what has been said I will have to pull the motor from the gear housing in order to somehow remove the worm gear and release the nylon gear so it will move up the shaft and expose the bushings underneath it. Which brings me to the problem of the brushes on the motor shaft. Someone mentioned using a paper clip to slip all that back together. How does that work? I always have a problem holding them back against the spring tension until I can get the shaft in between them on other things I have worked on. I suspect there is no access room to use something to hold them back. Unfortunately I have began to lose the dexterity of my fingers. I have new invited guest Arthur and his wife Ites have come to live with me.
 
[Boomdriver:

Thanks; Driving? The local TV weather isforecasting "SNOW" starting today (4/21/12) and going through Tuesday(4/23/12) morning. This is the strangest Spring I have experienced in my life!

John:

As we all know I am NO EXPERT but (that is not going to stop me):

1.) I encourage you to carefully reflect on your present decision to only do one side. I am almost certain that the left side is in nearly as bad a bad shape as the right side.

2.) Starting on the left side will allow you to exercise the procedures without getting wrapped around the maypole of the "ridge" in the right side assembly.

3.) Regardless, on the basis of the comments received from others here I strongly advise you to "NOT" pull the motor from the gear housing in order to somehow remove the worm gear and release the nylon gear so it will move up the shaft and expose the bushings underneath it. As I understand your comment.

4.) The motor must be removed from the headlamp assembly and operating mechanism. This is in and of its self an interesting exercise in "technical reverse engineering" (jiggling the component).
(4-1)Selected features of the assembly "WILL" have to be loosened to allow access to the appropriate fastening devices (here we could have saved between 10-15 minutes per side if we had simply had magnetized screwdrivers/torex/etc or a shop magnet).
(4-2)The motor and gear housing is an integral unit. Once the component is on the bench separated from the assembly, removing the gear cover plate allows removal of the gear (remember to do this gently because of the fragile gasket). You need to be careful in doing this because there are flat brass bushings that may be lost in the thrill of getting the thing apart.
(4-3)Remember, the assembly appears to be one unit, but it is composed of:
(a) a gear,
(b) three torque bushing (consumable),
(c) a combined torque armature and axle assembly, and the
(d) brass bushings.
(4-4)In theory the gear and the torque armature and axle assembly will just lift out (remember the flat brass
bushings as they "MAY" come out with the assembly or remain in place??).
(4-5)THERE WILL is some resistance from the sacrificed torque bushings which will look just like either course ground flour or the porridge I experienced. REMEMBER. Loosening the motor housing slightly goes a long way towards easing the removal and reinsertion of the entire gear assembly.

5.) The unique characteristic of the passenger side is apparently the "ridge" which requires a little extra relaxation of the engagement tension between the worm drive and the gear face (I think). Please DO NOT do more that loosen the motor housing. This will require more intense "technical reversing engineering" for both the dismantling and reassembly of the motor/gear component.

John, for the record, I used my mechanic for this evolution because I have problems with my retinas. My vision is corrected to 20/20; but dealing with "small" items is problematic for me and situations where I must get "close" to look at something with low light and or different visual accommodation factors is very, very troubling and is NOT correctable. In retrospect, the only thing in this evolution that "might" have caused a problem for "me" was the "pin" removal. I just didn't know what to expect. However, I was pleasantly pleased to discover that these headlight components are very robust and not prone to accidental damage from sight impaired or ham fisted mechanics. However, not keeping track of the various parts that may be placed on the bench is sure to cause one to question one's own skill sets.

Finally, to fix this you simply need the "torque bushings" and a copy of the Zip instructions, the visuals from Vetteoz, and TedC's and Roger's comments and observation. I recommend having the Zip document in front of you at all times. The visuals are easily relatable to the Zip instructions. And when you think you might have a problem TedC and Roger have observations and suggestions to help. Since you are going to open up an assembly I strongly urge the inclusion of a new gasket. It appears that the nylon gear is robust enough to not have been damaged by the failure of the torque bushings so replacing the gear is purely an option (remember we only changed ours because we had them). ALSO DO NOT FORGET TO APPLY A LITTLE WHITE LITHIUM GREASE TO THE GEAR before reassembly. It should take only 4-4.5 hours for both assemblies unless one has to make tool runs. I hope this provides a little more clarification.

Charles
 
Ok today was the day to work on the headlight motor. Thanks to all of you for your input I used a little of this and a little of that and got it done. Along the way I also created some more information on this job.

Yes the bushings were gone. I had a piece of high density 1/2" nylon dowel so I cut a button and found out it was a little to big in diameter. I took a piece to my drill press and turned it down to the right diameter and then cut off three pieces that fit perfectly.

Now I had the problem on getting the nylon gear to go back over the worm gear. For some reason the gear was molded with a solid band under the gear teeth. I took a three corner file and notched that band with three of the tooth valleys.( The worm gear only cathes one maybe two teeth ) I located this at the tip of one of the corners of the triangle that is molded on top of the gear. I did this so I would be able to find it later if need be. Once I lined up those notches to the worm gear the whole thing slide back into place without any effort.

On another day I think I will look into the right side bushings.

Thanks again for all the help. Each piece of information added to my being able to make this work.:beer
 

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