Alright,

So my situation is this..

My cruise control works, it holds speed just fine, and works immediately as soon as I press the SET button...

BUT when I'm cruising at whatever speed, and push the +1 MPH slider over, nothing happens....

Why is this??

 

Without sounding like a D+ck, this will be the best money you ever spend!.

 

Could be the cruise switch on the signal lever or a faulty cruise module under the dash. But yes, as TTOP350 stated, a repair manual is the way to go. They walk you through trouble shooting on most electrical problems and tell you where things like, where the cruise control module is located. Now they don't make the module anymore, so you may have to find one in a bone yard, If that's the problem.

 

Um...... I'm not sure the cruise control in a 3rd gen ever had the +1/-1 feature built into it. I could be wrong.

If you hold the ACCEL button in continuously does it accelerate or do nothing?

 

Alright, I know for a fact that yes, my GTA came with it from the factory, and that the cruise lever works (I know this because I swapped it over from my other GTA which had completely functional cruise control)

When I hold the ACCEL button over nothing happens... In my other GTA it would increase by exactly 1 MPH (I say this with 100 percent certainty for I had the Digital Dash option) and like I mentioned, this is the same cruise lever that worked in the other car.

 

Give me a bit to get at my manual. I just moved... the +1 mph should work as he says though. Chances are it's a bad module or switch or something.

 

After looking at my manual. There's no troubleshooting procedures at all. All it does it tell you where stuff is and how to take it appart and put it together. There is a cruise control switch at the base of the brake pedal. Same bracket as the brake light switch. I've broken that a few times. Without taking my cruise control lever appart and checking apparent resistances and stuff I don't think I could help. There is a module for it behind the instrument cluster. Top right? And then there's lots of stuff in the engine bay for it. It uses vacuum and there's a servo assembly in the engine bay for it as well.