Cruise control inop

[Jetjock]

When I got my Ruby Red Z last April, I discovered that the cruise control did not work. At the time, I thought it was an easy fix, just check the hoses. I took it down to Gordon for him to take a look at it. He checked the vacuum and it was good. Check the dump switch and it worked fine. Switched out the stem with my other ZR-1 and that didn't do it. Finally, switched out the cruise control module with one that Gordon had and that didn't do it. I checked the clutch switch and it is clicking like it should which doesn't necessarily mean that it's working but that means that the adjustment is okay. Buying a test light to run through the diagnostics in the service manual. We did find out that someone put a 5 amp fuse in where it should have been a ten. We did find out that the LTPWS module has been fried because it would not enter into diagnostics mode. The cruise and the LTPWS share the same fuse. Looking for suggestions as to what next. No speed sensors codes shown.

[GOLDCYLON]

When I got my Ruby Red Z last April, I discovered that the cruise control did not work. At the time, I thought it was an easy fix, just check the hoses. I took it down to Gordon for him to take a look at it. He checked the vacuum and it was good. Check the dump switch and it worked fine. Switched out the stem with my other ZR-1 and that didn't do it. Finally, switched out the cruise control module with one that Gordon had and that didn't do it. I checked the clutch switch and it is clicking like it should which doesn't necessarily mean that it's working but that means that the adjustment is okay. Buying a test light to run through the diagnostics in the service manual. We did find out that someone put a 5 amp fuse in where it should have been a ten. We did find out that the LTPWS module has been fried because it would not enter into diagnostics mode. The cruise and the LTPWS share the same fuse. Looking for suggestions as to what next. No speed sensors codes shown.


Is the brake switch centered on the brake pedal arm? If its not the cruise wont set.

[Jetjock]

Well, good question. I know that the dump switch works because Gordon was holding a vacuum meter in front of me when I hit the brake pedal. I haven't checked the alignment yet. That's now the next step right after I get my wife some coffee. Apparently, she ran out and I didn't know that. My fault, obviously. Funny how priorities get changed around like that.

Thanks dude.

[GOLDCYLON]

Well, good question. I know that the dump switch works because Gordon was holding a vacuum meter in front of me when I hit the brake pedal. I haven't checked the alignment yet. That's now the next step right after I get my wife some coffee. Apparently, she ran out and I didn't know that. My fault, obviously. Funny how priorities get changed around like that.

Thanks dude.

Happy Wife ='s Happy Life

OK let us know hopefully thats it.

[We Gone]

Had the same issue when I got my 93. was the clutch switch out of adjustment.

[Jetjock]

Had the same issue when I got my 93. was the clutch switch out of adjustment.

When you say out if adjustment, was it not switching on and off or was it not hitting at all? What did you do to readjust it?

[Schrade]

Gordon Killebrew couldn't fix it?

And he wasn't able to even tell what was wrong?

:confused:

[Jetjock]

Gordon Killebrew couldn't fix it?

And he wasn't able to even tell what was wrong?

:confused:

To be fair to Gordon, his service manuals were loaned out to someone and they were either destroyed or something happened to them. He suspected either the stem, the cruise control module or the clutch switch. I eliminated two of the three items. I have the manuals for the 93 so I'm running down there right now and see if we can checkout the system.

[Mystic ZR-1]

Gordon Killebrew couldn't fix it?

And he wasn't able to even tell what was wrong?

:confused:

Then, it ain't broak...

[We Gone]

When you say out if adjustment, was it not switching on and off or was it not hitting at all? What did you do to readjust it?

It was depressed keeping the button pushed in. If I remember correctly I turned the white plastic nut to move the switch back to release the switch.

[Jetjock]

I checked that this morning and it is clicking on and off. I started the diagnostics and discovered that there was no signal from the speed sensor to the cruise control module. I know the speed sensor works because the volume increases when I punch it and my speedometer works. I'm going to rig a jumper and see if that works from another source.

[Jetjock]

I'm not sure if I am reading this correctly but the service manual didn't exactly state the condition with which to test the speed sensor continuity. Making an assumption that key on, engine off and cruise on. Anybody else think that?

[Schrade]

CC diags starts here (http://www.zr1.net/forum/showthread.php?t=21076), with detailed snappics, post 33.

I have a suspicion that Mr GK cared not to attempt contortion exercises necessary to access CC module, which is ABOVE the CDM module under P side dash. That's where CC diags begins. All else is in vain.

http://www.zr1.net/forum/attachment.php?attachmentid=2655&stc=1&d=1378165933


2 circuits in the harness must be jumped for Test 1

http://www.zr1.net/forum/attachment.php?attachmentid=2658&stc=1&d=1378166282

[Jetjock]

[QUOTE=Schrade;205481]CC diags starts here (http://www.zr1.net/forum/showthread.php?t=21076), with detailed snappics, post 33.

I have a suspicion that Mr GK cared not to attempt contortion exercises necessary to access CC module, which is ABOVE the CDM module under P side dash. That's where CC diags begins. All else is in vain.

Not true about that. He crawled under the drivers side and unfastened and then reattached the carpet part of the bolster since I have a torn shoulder muscle and can't reach the firewall with my right arm. You should have seen the stump of his finger. It started bleeding along with the other scratches on his right hand. He fixed a bunch of other stuff before we got to the cruise part. We were running out of time since I had to get back home. We did determine that it was an electronic issue since vacuum was working.

By the way, this is a 93 ZR-1. No CDM. It's in the back behind the pax seat.

[Jetjock]

Is the brake switch centered on the brake pedal arm? If its not the cruise wont set.

Dude, I followed the electrical diagnostics and it lead me to the stoplamp/cruise brake switch. I looked at the brake switch and it was centered although the clutch switch was hitting in the middle. I suspect that the brake switch is the culprit here. I plan to check it this morning. Had company come over last night and they stayed overnight. Hopefully, if it is bad, I can get another or repair this one.

[Schrade]

I have mine left over from auto conversion; 14043256 GM pt #. Looks like it snaps open readily for testing.

If yours fails continuity test, you can have mine for postage (never subscribed to 'new part Plug n PRay' diagnostics ;) ).

[Jetjock]

Got the cruise control to work again with help of Gordon Killebrew. Took the car down there with manuals, showed him I found out and he went right to the problem. Bad clutch switch. He re-engineered it to work and it was fantastic! While we were at it, he got the LWTPS to work again, all I have to do is put the new module back in the car. Found out a lot about the 93 car and how different they are from the earlier ones.

[Fully Vetted]

I thought for sure it was going to be the Nut behind the wheel ;)

I don't think I've ever seen Gordon fix only one issue.

[Jetjock]

I thought for sure it was going to be the Nut behind the wheel ;)

I don't think I've ever seen Gordon fix only one issue.

Actually, he did fix only one issue. The LTPWS he had already worked on but it was a different module. He simply switched modules and it worked. We talked about your car for a bit but decided that to fix the car, we would have to fix the driver first. Seems all of the problems originate in the drivers seat!

Are you going to Carlisle or is that too much of jump for you? It's about 1300 miles from Dallas. Just a hint but you can stay at my house and leave from there. It's only 700 miles give or take from where I live.

[Scrrem]

Got the cruise control to work again with help of Gordon Killebrew. Took the car down there with manuals, showed him I found out and he went right to the problem. Bad clutch switch. He re-engineered it to work and it was fantastic!

My cruise is not working either, may check this. So how did he re-engineer a bad clutch switch? Was the switch bad or just need to be repostioned to make better contact?
Rich

[Jetjock]

First, you have to determine that it is a clutch or brake pedal switch. I followed the diagnostics in the manual and determined that it was one of the switches. There are three switches: one for the clutch and two on the brake pedal. The clutch handles the electrical disconnect and the other switch of the dual does the vacuum dump. The other switch on the brake pedal does the upper brake light. He checked both the clutch and the brake pedal switches and he took off the cover and found bad contacts on the clutch switch. He took the working switch, changed the cover and reinstalled the switch. I only have two switches now as it was a redundant switch to disable the cruise control. The switches have different diameters so you have to be careful about that. I have the vacuum dump and the electrical disconnect in the same switch on the clutch.