Alright, now I did a search and that brought on some more questions for me before I begin. The three things that seemed the most popular for why cruise control units aren't working is vacuum leak, bad switch at the brake pedal, and servo unit by the washer bottle. However, my vacuum lines seem ok as my a/c controls function properly directing the air to the proper vents (which was one way to tell if there was a vacuum leak apparently). My question there is is it possible to have proper a/c controls and still have a vacuum leak on the cruise circuit?

Next was the switch. I was wondering if the switch works the cruise separately than another switch for the brake lights or if it was integrated? Because my brake lights come on when I hit the pedal.

Lastly, servo unit. It seems ok and like the vacuum should pull it down. Any way to check this without replacing it? How much is it to replace? I don't have a vacuum gauge. And if I had a vacuum leak on any circuit, wouldn't that cause running/idling issues? The car seems to run fine with no leaks on the vacuum that I can tell, however, there is a slight surging in idle when it is cold. But I did build the motor less than 1000 miles ago and the cam is different as well as the computer chip compared to what is actually in the motor. (cam is off, injectors are different, heads are different, no EGR, and the chip is a stock 350 chip). Even warm it tends to idle like the cam is a bit stouter than stock...which it is. So I didn't think anything of it really.

Anyway, any help here would be appreciated as well as any other ideas as to where I should start based on the above description to what someone may have already found in the past that is usually the culprit in a case like mine.

 

I know there is a ground wire by the drivers side hood hinge. There is also a sort of control box for the system on the passenger side of the dash ... if you don't have a VSS signal it won't work. check to make sure the switches wire are plugged in it's a flat connector at the bottom of the steering column.

 

Thanks. That is the other one I forgot to mention that I had seen in the search. I will definitely check that as that would be ideal if that's all it took to fix it :-p

 

In the case of my '89 Jimmy 4.3L with AC, my AC vacuum activated vent controls are almost completely ineffective. In some positons the vacuum leak noise is so annoying I have to move the selector switch into "inbetween" positions to make it a little quieter.
But, my cruise works perfectly. So AC control vacuum leaks may not always be an indicator why the cruise doesn't work. Not saying that that is always the case, but it can be disproven in some.

Wish I could help you more.

 

Every bit helps. I was sort of thinking that anyway as I have lost a/c controls on my '94 T/A before and it did not affect the cruise either. It turned out to be a simple vacuum check valve in the line to the e/c controls. I was just not positive if they were two totally different circuits and if a vacuum leak anywhere would cause a running issue with the motor.

 

on my 89 camaro, cruise control module is @ middle of dash,a little more pass. side,the brake switch has a vacuum line direct from servo to it,after troubleshooting my system,with some jumpers,my multi function switch on column is the problem,but since blinkers worked fine,i not fixed it,guess the same switch is why my windshield washer doesn't work either,its a black bundle wire with the seperation at the connector on the column