Headlights won't open

[srs244]

I just replaced both actuators on mine yesterday. Pretty easy to do....Now they both go up and down together and fast......I traced the lines and checked both relays before I ordered the Actuators and everything was fine. The Actuators was the fix.....

just curious if you checked the actuator seals first. it is very unusual for the actuators themselves to go bad unless they are in such bad shape that they rust through somewhere and are no longer a "sealed" unit. the rod seal is usually the problem and is a bit more economical than replacing the actuator (under $10 compared to about $100 for an actuator). i still have an original actuator on the driver's side of my 78 pace car and it works perfectly since the seal was replaced. there wasn't an actuator on the passenger side, so i had no choice but to replace it, lol.

steve

 

[Daryllawman]

Yes I first ordered both seals and the boots....that made them come up just a little......then I got the actuators.....that was the fix.....I have been checking out the system for a few weeks...they work good now.....

just curious if you checked the actuator seals first. it is very unusual for the actuators themselves to go bad unless they are in such bad shape that they rust through somewhere and are no longer a "sealed" unit. the rod seal is usually the problem and is a bit more economical than replacing the actuator (under $10 compared to about $100 for an actuator). i still have an original actuator on the driver's side of my 78 pace car and it works perfectly since the seal was replaced. there wasn't an actuator on the passenger side, so i had no choice but to replace it, lol.

steve

 

[srs244]

glad you finally got it!! it's always been amazing to me that for a vehicle that was supposed to be technologically ahead of the competition, they used a system that proved inadequate years before when they replaced vacuum wipers with electric ones, lol. it took them another 40 years to figure out that electric motors on the headlamp doors was a good idea also!!

 

[craig32]

I will help out furthur if needed.

-Vrod

vmrod,
headlight and override switch were not changed. I followed all your instructions, everything worked as needed, except the headlights still won't come up. I took off both relays and they seemed to be working - as in not leaking. Again, I have 20 lbs vac. in the hose going into the canister, 15 lbs coming out of it, and 20 lbs in the hose that goes to the 'T' at the top of the relays. Both actuators appear to have good seals, as blowing in the hose makes them rise, as well as my eyes pop out. WHAT IS LEFT???
ad
Thanks again, I hope you have more. . .
Craig

 

[srs244]

vmrod,
headlight and override switch were not changed. I followed all your instructions, everything worked as needed, except the headlights still won't come up. I took off both relays and they seemed to be working - as in not leaking. Again, I have 20 lbs vac. in the hose going into the canister, 15 lbs coming out of it, and 20 lbs in the hose that goes to the 'T' at the top of the relays. Both actuators appear to have good seals, as blowing in the hose makes them rise, as well as my eyes pop out. WHAT IS LEFT???
ad
Thanks again, I hope you have more. . .
Craig

it would appear that the only thing left would be to swap out the actuators (see the reply from daryl above). it's possible they are leaking internally even though the rod seal and boot is good. perhaps you can find someone with an extra one on the shelf that you could borrow to check it out.
just my suggestion based upon all the testing and results you have given us.
steve

 

[craig32]

Steve,
I actually did change one of them. They start to come up but only a couple inches. If you lift up on one, the other one drops accordingly. If you press down on it, the other one raises. I don't think seals are bad or it wouldn't do that. Imagine how ad I'll be if I dump $200+ in it and it doesn't fix it. . .
Craig

 

[vmrod]

Here is another test. This one will help you troubleshoot the relays. Also, use this diagram.
http://home.comcast.net/~chadwick.robert/HEADLIGHT-SCHEMATIC.pdf

First, just to make doubly sure that your controls are working do the following, otherwise skip to #10.

1.) There is a vaccuum line that leads to the relay(s), which comes from the firewall. (This is the hose that comes from the override switch.) Disconnect this hose from the relay(s). If you have both the override switch and the headlight switch 'off' then there will be vaccuum at this disconnected hose. (if the car was running)

2.) Pull the override switch, so that it commands the lights to open. Since you disconnected the signal hose (see above), this will not be what opens the lights. You pull the override switch just to prevent a vaccuum leak in the system. The lights are commanded to open, because the signal hose has been disconnected. (fail safe signal system)

3.) Start car and observe headlights. Rev up car a few times and notice possible changes in movements.

4.) If headlights popped up, then there is something wrong in the control circuit.

5.) Reconnect hoses. end of test.


10.) This test will help diagnose the vaccuum relays. Use the PDF diagram above to help out with the task.

11.) You will need some pieces of hose for this test. The size may vary. As you disconnect hoses, either mark them with tape, or gain a complete understanding of how the system operates as a whole. Either way makes reconnections a snap.

12.) Disconnect the appropriate hoses and remove a relay from the car. Locate relay on PDF diagram.

13.) With the relay 'on the shelf' you should be able to freely blow thru the ports marked 'C' and 'N.O.'. (Note: The ports are likely not labeled as such, but determine ports per diagram.) Now, cover up the 'N.O.' port and try to blow again. If you can still get air thru, then you have found a problem with the relay. I suppose that a tiny bit of flow may be permissable, but in theory it should be fairly airtight.

14.) Locate the port on the relay where the signal line connected. (the top line on the diagram) Suck in on this, then blow into it. You should be moving a small diaphram up and down inside the relay. You should not be able to freely suck or blow, but only enough to allow movements inside the relay. If you can freely blow into this port, then this is a problem relay.

15.) Since you were having fun with that signal port on step #14, let's do it again. (I'm assuming that it is functioning properly, otherwise this step is for nothing.) Suck on the signal port until you cannot suck anymore. This will change the position of the internal valving inside the relay. Now plug up the port without losing that vaccuum.

16.) Blow into the 'C' port and feel if it freely comes out of the 'N.C.' port. You should feel it. Now put your finger over the 'N.C.' port and blow into the 'C' port. If you can freely blow into it, then the relay is leaking internally and needs replacing.

17.) Replace relay and repeat for other relay.

Relay operation:
The relays always have vaccuum applied on the 'C' port. (with engine running) This vaccuum is channelled to either the 'N.C.' port or the 'N.O.' port. (normally closed or normally open) The signal vaccuum tells the relay to switch from using the 'N.O.' port to the 'N.C.' port. (That is why when the signal vaccuum is disconnected, the relays revert to using the 'N.O.' port)

Lastly, if you find the relay is bad, then why not open it up and see how it works. If you are careful, you might be able to repair it. However, it is likely to suffer from a cracked diaphram or dried out rubber internals.

I hope this helps you.

On a separate note, if you wanna try out the actuators, why not hook up your main vaccuum line (from the canister) directly to the 'open' port on the actuator. If you are not sure which port is which, then try them both.

Craig, let me know if this helps. The headlight system is really not as bad as it seems once you understand it, and there is not too many things left for you to check.

 

[srs244]

Steve,
I actually did change one of them. They start to come up but only a couple inches. If you lift up on one, the other one drops accordingly. If you press down on it, the other one raises. I don't think seals are bad or it wouldn't do that. Imagine how ad I'll be if I dump $200+ in it and it doesn't fix it. . .
Craig

craig
i agree. not something that you just want to arbitrarily swap out (the $200 is a killer, lol), that's why i suggested that perhaps you could find someone with a spare on the shelf to give it a go. i guess in my case i was kind of unintentionally forced into getting them right. when i got my car, it didn't have either of the vacuum relays, and was missing the passenger side actuator. so all of those parts are brand new in the system. even after putting in the new parts and changing out the vacuum lines, check valve and filter to complete the system correctly, the headlamps still wouldn't work. they tried to rise but it was a half hearted effort on their part, lol. in my case the only thing left was the boot and seal on the one actuator that was original to the car (driver's side). it was the only thing left that hadn't been changed out or re-fitted to complete the system. i wish i had some other suggestions, but i think at this point you have it narrowed down to the relays or the actuators. good luck.
steve

 

[craig32]

Hey Steve,
Let me go a little deeper for you. . .I took it to the GM garage and told them to 'troubleshoot' it for me, they came up with 'needs a new actuator' for $130 + $108 labor. When they got done goofing around with it, they had hoses on the wrong places and some weren't even on. They also said there were pieces missing, and it only cost me one hour's labor for them to scratch their heads for 2 hours and make it worse. I got another actuator and put it on myself - still nothing. I called another garage that 'specializes in Corvettes from 1981 to present' I tried to tell the guy what I had so far so he would know where I was. He said "I don't give lessons over the phone" Also no Saturday hours, my best bet would be to drop it off. Did I mention this place is like a block from the ghetto? I'm not paying someone a fortune to do something I could do myself just because of the nameplate (that is missing from) on the back. I've got to try vmrod's new directions after supper, hopefully I get something figured out. Thanks for helping out, I'll get it eventually.
Craig

 

[craig32]

vmrod - latest results. . .
with the engine running, when I pull the vacuum line at the 'T' (signal line?) the headlights try to raise like when I pull on the light switch. Is that right?
As opposed to taking the relays out again, I tested each by taking the 3 big hoses off of the bottom. With the engine running, I can blow through a hose on the middle port and it comes out the top, with the engine off, I can do the same and it comes out the bottom port. (One side did seem a little tighter than the other). Is that correct?
I didn't try hooking up the actuator to the middle port. I'll have to try that later.

End result - SSDD - still doesn't work! :confused

Thanks again.
Craig

 

[vmrod]

Craig, you are correct in that pulling off the tee-ed line (signal) would try to raise the lights with the engine running. If you are getting the same results when you activate your light switch or your override switch, then these items are working.

I haven't worked on mine in some time, so I don't remember which port is where on the relay. The 'C' (common) port is the port that the vaccuum canister connects to. Locate that port, then locate the other 2 ports and determine which one is which.

You are on the right track so far. The idea is that there is a valve inside. You should be able to blow into the 'C' port and the air only come out of 1 of the 2 bigger ports. When the relay changes position, the air comes out of the other port. Remember to try plugging the hole with your finger. That way, you can tell if air is bleeding thru the relay.

 

[srs244]

craig,

fortunately the headlight system isn't that difficult to understand (fixing it and locating the reason for any problems, however is a regal pain in the you know what, lol). it is one of those things that you can deal with if you have the patience. you are definitely on the right track. it is still a mystery to me why chevrolet stuck with such an antiquated system for as long as it did when the technology was definitely there to make an improvement. that said. by some chance do you have the color coded schematic of the system?? i found it to be a significant help when i had to put mine back together again. i will be more than happy to see if i can find it and get it to you (scan and email if you wish). just let me know. if you keep checking the components of the system, and they all seem to function the way they should, it is possible that you have one or more of the hoses connected incorrectly (thanks probably to the botched "professional" service you had done previously). i know you are well into this project, but i don't remember seeing if you changed out the vacuum lines themselves (i assume you did, and that's not an issue). if you didn't, sometimes the very ends of the lines where they go onto the various nipples crack. the problem can be 'short cut" by nipping of a bit of the hose ends to get a better seal. i know this is probably also been covered, but did you make certain that the check valve is installed correctly?? (just taking stabs in the dark at this point trying to cover stuff that might have been overlooked previously). hope spome of that might help out.

steve

 

[bagger]

Thanks vmrod. I'll check this out. Right now when I activate the override I can hear air hissing from the front around the actuators area. Hopefully it's something simple.

 

[craig32]

did you make certain that the check valve is installed correctly?? hope some of that might help out.

steve

Uh, what check valve? And no, I didn't replace any hoses - yet. Thanks again for more suggestions.

Zgator - sorry to butt in on your thread - are you getting your problem solved?

vmrod, I will try the other test with the canister vacuum directly to the actuators probably tomorrow. Thanks again all.

Craig

 

[srs244]

check valve

you should have two "devices" in the line almost immediately after the connection to the intake manifold (that's where the vacuum for the system comes from). they look like little "flying saucers" about the size of a silver dollar each. the one closest to the intake manifold connection should be a filter (it will be plastic). the next one in the line toward the rest of the system (and farthest away from the manifold connection) will be the check valve (metal with 1 port in and 2 ports out). it's purpose is to keep vacuum from leaking backwards in the system to the open intake manifold connection. it is what effectively maintains vacuum "pressure" in the reserve tank and the remainder of the system when it is idle.

just a suggestion, if you haven't changed out your vacuum lines, you really should invest the approx $50.00 for a complete kit and do it. even if your lines are not the problem, if they are original (read "old" here), they will eventually cause you problems from being dried out by the engine heat over time. it is very possible that you have a rupture or a small slit in one or more of the lines that you can't see or feel and you will drive yourself nuts trying to get the system to function without finding them. it could also be something as simple as a deterioration of the ends of the lines where they seat on each device.

sorry to add additional things into the mix, but it will probably end up being something fairly simple in the end.

steve

 

[chevyaddict]

I'm just replying to this thread so I can easily find it in my user postings. hee hee.. I orderd what I hope will fix my problems... the seal kit but if it doesn't I want to refer back to this thread!!!

 

[craig32]

vmrod and Steve,
I took the vac line from the back of the canister and put it directly on the actuator, and it did the same thing as when I turn the lights on - start to come up slowly and stop about halfway. The hoses in that area are a little 'suspect', but I don't know if they might be leaking or just the fan pulling air through the radiator. So, is this sounding like a vacuum leak, and not the actuators or relays? Thanks again.
Craig

PS Dawn, like the new pic!!

 

[vmrod]

Well, you can check out the hose easy enough. Plug up one end of it, then go to the other end, disconnect it, then hook-up a mity-vac to it. If it holds vaccuum, then the hose is still good. However, if you had a crushed hose, then you wouldn't know it with the mity-vac test. Perhaps you can follow the hose and inspect every inch of it. If in doubt, just replace all of the hoses.

Since you had temporarily hooked up your vaccuum hose to the actuator (bypassing the relay), and you get the same results, then I think you can rule out the relay as a problem. It must be your hose, or the actuator(s), or both.

My hose was collapsed at the holding clamp, near the alternator. I cut the bad piece out, and spliced it back together. One of these days, I wanna replace the rubber with metal tubing.

 

[PawBobby]

Finally after a month I just today got the headlights on my 82 CE to work right. I left it at a garage for a week--they worked for 2 days?--- I knew nothing about how they were supposed to work so I got a troubleshooting guide and a vacuum guage and went to work.:confused

I didn't know that if the headlights stayed down meant you had vacuum.

First I tested the vacuum from the engine through the over ride switch and the headlight switch by making sure they were off and checking vacuum at the T conector that provides vacuum to the actuator relays, they had vacuum.

Then I checked the control vacuum out of the canister :confused LOW! Took the canister off it was cracked at the rim leaking vacuum. As you guys know they don't make those anymore so I used JB weld . Worked fine. Solved the contol issue. Lights still not working properly.

Checked the passenger side actuator--vacuum sucking straight through.:confused Obviously the diaphragm inside was busted.

Ordered a replacement which fixed the problem of vacuum sucking through. Still didn't fix the lights.

Checked both actuator relays and found a curious situation Even when I turned the headlights on which should have taken away the vacuum allowing the lights to go up. I still had vacuum :confused So I was back to square one. I checked again at the T going to the actuator relays and found when I turned the lights on I still had vacuum. Spent today checking that and found 2 things. the mechanic that I had taken it to initally must have crossed the hoses to the over ride switch and the headlight switch because I KNEW when you pull that switch it should break the vacuum and allow the headlights to come up. So for the heck of it I switched them and it FIXed it !

Headlights work GREAT and FAST!!

Thanks for the read and if I can be of any help just email me.

PawBobby

 

[Daryllawman]

Great news......I know I was happy when I got mine fixed....they can be a pain....