They have a relay I would check itor your speed sensor went out

 

Is there anything in the cruise control system that could be affected by temperature?
When outside temperature is 40° or below it works every time I engage it.
Outside temperature 40° to about 60° it works sometimes, maybe ½ the time.
Outside temperature >60° it NEVER works.

Took me a long time to correlate the temperature factor with cruise operation, but I have watched it thru 2 wintwers and summers and there IS a correlation.

Thanks anybody for any reply.

 

Checked relay, don't know where the speed sensor is or what it looks like. I'll find out and check it out.

 

I can't help but think it is the brake light switch. I wondered about the temperature facture and the one person's post about greasing the switch. Do you have the heater blowing the hot air on your feet in the winter?

 

yes, I have checked the brake light switch and occasionally when I kinda "jiggle" it around the cruise will work, but not always. Haven't thought of lubricating it. Will try that. It's very difficult to get to up under the steering column.
Yes, I usually have the heater on, but not always (this IS SW Texas, air cond. & heater used on same day).

 

It was difficult to know if the grease ever worked its way in, so I opted to replace it. It was so cheap on line I figured it was a low risk chance. It worked and I have not had a problem since. Good luck.
QUOTE=agss241;306897]yes, I have checked the brake light switch and occasionally when I kinda "jiggle" it around the cruise will work, but not always. Haven't thought of lubricating it. Will try that. It's very difficult to get to up under the steering column.
Yes, I usually have the heater on, but not always (this IS SW Texas, air cond. & heater used on same day).[/QUOTE]

 

Is the brake light switch the one by the brake pedal way up under the dashboard and steering column? Really hard to get to.

 

Yes that sounds right. I had to lay on my back on the floor. Very tight fit. But once you get in position and all your tools at hand it is and easy fix. A small light is essential.

 

Thanks very much for the info. I'll give it a try. It'll be a tight fit, I'm 6'4, 280#, but I spent my career as a Navy submariuner so I've been in tight fitting places before. Thanks again.

 

Just replaced my brake switch on a 2008 GMC 1500. The cruise would work intermittently, then went totally dead. I did have the same--work in the winter better than summer problem that was mentioned in an earlier thread.

Bottom line is I got a new brake switch, (after losing the spring in the old one trying to clean it up), from a GM dealer for 23.27 after tax. Popped it in and everything works great!! The clip is kind of a PIA, but other than that if you pay attention to how it comes apart the reinstall took about 10 minutes.

Thanks to everyone for their help!