92 cruise control problem

[torranosaurus]

Hello.

Just bought a 92 Sierra and the cruise does not work.

I do not know where to start since I cannot even find a fuse for the cruise.

How can I diagnose without just throwing parts at it?

Thanks.

Andre

 

[1997SierraSLT]

just looked at my Chiltons manual (8055) and it's worthless.

[kilbornf]

Google it you, will get all kinds of answers.

[93gmc$$]

First thing to check are the limit switches at the Brake (and Clutch). Make sure they are not engaged with the pedals not depressed. Next are the Vacuum lines to the cruise control resevoir. Make sure they are connected, not rotted out, etc.

[thx1138v2]

I ran into a problem on my '94 Sierra that may be related. Sometimes the cruise control would work and sometimes it wouldn't. And what was really weird was that sometimes the wipers would work and sometimes they wouldn't. I was working 14 - 16 hour days at the time and just lived with it for a while. I finally got tired of the wiper problem and repaired the circuit board in the wiper motor and, wa la!, the cruise control was fixed also.

 

So check that the wipers work also. If not, fix that first. I'm not sure that it applies to the '92 but if the wipers aren't working you'll need to repair that anyway.

 

I had another weird problem like that when the trasmission wasn't shifting correctly. The speed sensor signal ran through a trace in the brake light switch down by the petal which kind of makes sense since it should shift when you apply the brakes. I traced the circuit out and the the brake light switch was the cheapest part in the circuit to replace. The truck being 15 years old at the time, I thought it was probably due for a brake light switch anyway. So I did that and the shifting problem was fixed also.

 

I'm not sure any diagnostics would have pointed out either one of those problems.