I tried-out the Cruise Control again to see what was going to happen. Bad things happen. Like it DON'T CANCEL when you tap the Brake. Plus, it won't stay-put at the SET Speed. It likes to accelerate without being asked!! What is does is going to crash this Monte if I don't do something about it.

I was on my way over to my daughters and did a test. Set it a 45 and was enjoying the ride. That's when the Car decided we ought to be going 50! Then ... 55! So. I tapped the Brake and found-out that the Cruise Control has a mind of it's own. The car was still putting-on power so I "Hit" the Brake Pedal ... and that didn't CANCEL the acceleration.
I braked against the car wanting to go and shifted into Neutral ... and the Monte hit the limiter and was pulsating at 48-Hundred RPM's ... until I shut-off my Ignition and restarted the Car -- On-the-go!

Once the Car was shut-off, the computer got off the Cruise demand and I was back in normal driving mode.

I need to troubleshoot the Cruise Control and I don't have a wiring diagram that easy to read.

This ought to be a couple of days worth of hair-pulling fun!

 

There was a problem like this on the Buick's for awhile in the early 2000's, I believe GM made a "service bulletin" I hope Craig gets around to set this striaght..

One thing I know aboutcruise control is that it is the brake light switch that turns it off when you hit your brake. I'm not so sure its your problem ,considering it speeds up on its own, but when you hit your brakes and your brake lights don't come on (reason being the switch broken), then your car will think its on a sharp hill and fight the brakes.

But if it is accelerating on its own like you say, I don't think the brake light switch is your problem.

 

The weather is supposed to get milder up here this week. I'm going to give the Brake Light a "Sensitivity Test" and see how much Pedal it takes to close the circuit. If I find that the Switch is closing "Late" ... I'm going to give it an adjustment and have the Switch close with just a touch of that Brake Pedal. I'd prefer to have it that way ... anyhow.

If it's not the Switch ... then, ... I'm going to see the help of the Pro's on the matter ... because its a safety related issue ... for sure!