Important! Parts List

[John Robinson]

I am looking for a Micro Fiche for my 93 coupe. I have been trying to find the GM part number for the cruise servo.

I have searched the web and this site for one I know some one must have one.

;help

 

[jp1]

servo part number

Looked it up in my parts book for you.

cruise control servo 93-96 = delco part number 25074627

 

[John Robinson]

Thanks for the information.and welcome to CAC.

I ordered a servo for the car and when it came it was about half the diameter of the original and did not work.

The Parts store needs the GM # to get me the right Servo. At this point they can not get a replacement before the 20th.

As I have said in other posts I have vacuum and the dump system is working and I can hear the transducer click when I turn the key on and then turn on the cruise.

At this point I am taking a leap of faith that the servo is the culprit. Yesterday I removed the servo and plugged the vacuum hoses. The car idles better now and the AC directs air better. I am hoping this means that the removal of the servo and plugging the hoses has proved that the servo had a vacuum leak.:J

 

[gmjunkie]

At this point I am taking a leap of faith that the servo is the culprit. Yesterday I removed the servo and plugged the vacuum hoses. The car idles better now and the AC directs air better. I am hoping this means that the removal of the servo and plugging the hoses has proved that the servo had a vacuum leak.:J

You may be on to something John!!I've never had one go bad that way,But that don't mean they won't!!

 

[John Robinson]

You may be on to something John!!I've never had one go bad that way,But that don't mean they won't!!

Junk Your answer either scares me or makes me feel better about the servo:confused When you say you never had one go bad that way do you mean the servo? I am asking because I have seen how good a diagnostician you are with other problems. You were right on with my window problem and gave me a lot of good ideas. And your suggestion to remove the seat to get under the dash to the brake switches made that job a lot easier.

If blocking off the vacuum and dump hose has improved the run ability of the engine would you suspect that the servo has a vacuum leak.?

 

[gmjunkie]

Junk Your answer either scares me or makes me feel better about the servo:confused When you say you never had one go bad that way do you mean the servo? I am asking because I have seen how good a diagnostician you are with other problems. You were right on with my window problem and gave me a lot of good ideas. And your suggestion to remove the seat to get under the dash to the brake switches made that job a lot easier.

If blocking off the vacuum and dump hose has improved the run ability of the engine would you suspect that the servo has a vacuum leak.?

Well John,If there is No Leakage from the dump switches,and after plugging vacuum off to the servo,and the car runs better,I would have to say that there has to be a leak in the servo!!I've never had one develop a leak in the servo,I usually find a Dump Switch problem or a problem with the switch in the Signal Lever!!

 

[John Robinson]

Junk

Thanks for your answear. Since my last reply to you I have removed the transducer and put loctite silicone around the oval rubber o ring. I also reconfirmed that when I have the key in the on position and turn the cruise button to the on position on the lever the transducer makes an audible click. Next I rechecked that I had vacuum and then I sucked on the dump hose and put my tongue over the hole and it did not bleed off.
Also on the Servo connector I have 8 volts between b and d and I have a test light on between term c and b+. The only thing I have not probed is the CCM. That is because one I did not want to tear into it and two I thought if I had the above conditions at the servo connector then it was shaking hands with the cruise. And so I value your input because I think I have gotten myself in a box and may not have the problem figured out yet.:W

 

[gmjunkie]

John,I was just thinking and wondered!!(Might be Dangerous!!)Have you checked the vacuum reserve tank to make sure it is not leaking or the hose disconnected to it??It's on the front side of the left front splash shield,Looks like a 6-7 inch round black ball,if its leaking or disconnected it can affect the A/C and Cruse!!

 

[John Robinson]

John,I was just thinking and wondered!!(Might be Dangerous!!)Have you checked the vacuum reserve tank to make sure it is not leaking or the hose disconnected to it??It's on the front side of the left front splash shield,Looks like a 6-7 inch round black ball,if its leaking or disconnected it can affect the A/C and Cruse!!

I will take it off tomorrow and check it for leaks. How do I do that?

Can I use an air hose to blow air into the tank?

Should I be able to feel vacuum at the hose to the tank with the engine running?

 

[gmjunkie]

I will take it off tomorrow and check it for leaks. How do I do that?

Can I use an air hose to blow air into the tank?

Should I be able to feel vacuum at the hose to the tank with the engine running?

No don't blow air in it, it might break the seam!!Draw a vacuum on it and see of it bleeds off!! Yes with the engine running the hose should have a vacuum on it!!!

 

[John Robinson]

Ok, I checked the tank and it is good. I also have vacuum at the tank.

Oh yes and I replaced the check valve a couple of months ago.:crazy

 

[gmjunkie]

Ok, I checked the tank and it is good. I also have vacuum at the tank.

Oh yes and I replaced the check valve a couple of months ago.:crazy

I guess you must have a leak in the servo.You've just about covered everything else!

 

[John Robinson]

I will update this post when I get the new servo. I should have it around the 20th of this month.

 

[John Robinson]

Servo no Cruise

I got a call that my new servo was in at the parts store this morning.

Now here is the fun part. Rushed home and put it on the car and it did not work. Bought some new vacuum hose and ran a new line from the check valve to the Servo. Still no cruise, it would not respond at all. Next I thought maybe the brake switch is dumping the vacuum so I put a piece of vacuum hose on the servo and blocked it off and also blocked off the hose to the brake switch. This should have told the servo everything was fine at the brake switch. With all this coming up with a big fat goose egg I went back to crawling up under the dash. I was looking for the cruise switch relay, which I never did find. While under there I discovered the brake and cruise switch's needed to be adjusted. Yee Ha I made the adjustments and put the seat back in for a test drive. Your right no cruise. Now it gets interesting photos to come.

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I found this connection to brake switch with the white piece taped between the white and red wire. It did not look factory to me. I checked continuity on the white piece which it had. Is this the way it should be?

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I believe this is the connection to the cruise switch. I have separated the connection and turned the key on and the cruise to check for power on the black, white, blue, red. Did not have any power should I be checking the other side of the connector for power?

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I found the cruise switch did not have any electrical connection to it. I have looked around but can not find anything that would connect. Does it have an electrical connection?

At this point I am about ready to give up.:cry:confused

 

[gmjunkie]

John,Tell you what,I have a customer 93 here right now and will be here for another week!! When I get the windshield out of it I have to do some repair to the dash,I'll pull the bottom off and take a Look see!! The only difference I can think of that would different than yours is that it will have 2 Vacuum Dump Switches because it's a 6sp!! I'll try to do it tomorrow but it may be Saturday!!

I know my 94 has wires going to one of the dump switch's!! Because when I got the car the cruse didn't work,and it ended up being the plastic T in the vacuum line between the two!!

 

[John Robinson]

And I think I have troubles

I was following your diagnostics on JimiJam95 and thought when it was done his troubles were over. Then the pictures of what happened just after he got it back. I know you are working on it again and it will be like Lazarus coming back to life. I appreciate you giving me your time and advice. I will wait in fact I may have to because I think that tomorrow I won't be able to move. At my age getting under the dash is not easy even with the top off and the seat out. The only reason I am able to do it now is I have lost 25# trying to control the bid D. The real truth is with the price of gas where it is I can't afford to have a mechanic work on it and I will not give up enjoying it to the fullest.