Strange electrical issue.

[Partsguy61]

A rather strange issue started about 2 days ago. On my way to work, the cruise control would randomly disengage. When I pressed the button it would engage normally and work just fine. I though that I may have bumped the brake pedal and caused it to disengage, but after making sure that my feet were no where near the pedal and it happened again, that wasn't the case. Last night I had the dog outside and while my truck was just sitting there, the brake lights came on and went back off. If the circuit for the brake lights is randomly being powered on, that would make the cruise disengage just as pressing the brake pedal would. Has anyone had anything similar happen to them and if so, what was the fix?

 

[OR VietVet]

Fix the Chevrolet Intermittent Electrical Problem for Good

The Chevrolet intermittent electrical problem can drive you crazy. These vehicles intermittently lose power to the dashboard, radio and electrical system. See two causes.

www.fixmyoldride.com

Check this out and it may help. May be a failing stop light switch and I was gonna look it up for you but AGAIN a post is made by someone with no vehicle info.

As a "Partsguy", is not the first question you ask when someone wants a part, "What is the year, make, model, engine size".....etc?

I say this in fun but it is frustrating to try to help with no info.

 

[Partsguy61]

Sorry for the missing info, but since I asked the question on a Tahoe/Yukon forum under 2000-2006, I figured the Make, Model and Year question would have been obvious. I guess not. 2002 Yukon SLT, 5.3Z. Anyway, I disconnected the stop lamp switch today as well as checked and cleaned the chassis ground as one of the techs at work suggested that. I asked the question here because none of the techs at work had any idea what could be causing it and I figured that hopefully someone here had heard of or run into this situation before, even the older ones.

 

[OR VietVet]

Ok, I can assure you that every vehicle under that 2000-2006 section do not all take the same parts. Likely that most of them are but I am not going to sort thru 7 years of vehicles looking to be sure of that, when the onus is on the person asking the question. For instance, I used to own a 2002 Tahoe LT. The throttle body on it was activated with a throttle cable but my 2005 is not the same. Plus, certain RPO codes make all the difference as to what parts are correct for the application. Plus, again, that 2000-2006 section includes 3 basic models. Tahoe, Yukon and Escalade.

Your thoughts about someone here maybe had run in to the same problem is a great assumption but still need to know the particular's in order to cross reference. Does that make any sense?

So, you said you did what a tech suggested at work but did not post results. Fix it? Still have the exact same problem? How many grounds and locations did you check/clean? When you disconnected the stop light switch, did you inspect it and the pigtail that plugged in to it? Check the female connectors in the connector housing?

I truly do hope that someone reads your question about the problem you are having and knows what it is but there are some members that will read and see no vehicle info and then just skip on by.

As I said, it was meant as all in fun but it also was meant as a reminder that things change from year to year, model to model, engine size to another engine size and of course, the RPO codes can be full of all kinds of info you need.

 

[ks03]

My first thought is looking for what’s aftermarket on the vehicle. #1 being, does it have remote start. Followed by, did it used to have remote start, or maybe a previous owner had remote start and didn’t remove it fully, or left exposed wires. Basically have you poked around under the dash for anything out of the ordinary, especially to do with the brake switch wiring. So then back to anything else aftermarket? Lighting mods? Something left connected to the obd port or spliced in? If I couldn’t find anything, I’d consider weighing replacing the brake switch with how I’d feel burning an equal amount of money to said brake switch

 

[swathdiver]

A rather strange issue started about 2 days ago. On my way to work, the cruise control would randomly disengage. When I pressed the button it would engage normally and work just fine. I though that I may have bumped the brake pedal and caused it to disengage, but after making sure that my feet were no where near the pedal and it happened again, that wasn't the case. Last night I had the dog outside and while my truck was just sitting there, the brake lights came on and went back off. If the circuit for the brake lights is randomly being powered on, that would make the cruise disengage just as pressing the brake pedal would. Has anyone had anything similar happen to them and if so, what was the fix?

On the 2007-2014 wagons, they have a brake switch above the pedal that when it begins to fail causes the cruise control to not work. Cleaning the contacts doesn't work, it has to be replaced with GM OE or ACDelco Professional for best results. I think yours has the same system but do not remember. It's a 5 minute fix and $20.

 

[OR VietVet]

In this case, his 2002 Yukon, his brake light switch is the same as a Tahoe and an Escalade and is part #D891A:

More Information for GM GENUINE D891A

Does show "Out of Stock at RA and indicates they sell a lot of them for likely the same reason that @swathdiver stated. There are other cross reference numbers, listed in the link, that can help find elsewhere as well.

 

[Partsguy61]

Thanks everyone for the info. Sorry if I came off as being short in my earlier post. I am just very frustrated with this as I'm towing my hot rod to Woodward next month for the Dream Cruise and could really use cruise control.
Ok, here's the entire situation. This vehicle did the same thing a little over a year ago. First I disconnected the brake switch and the brake lights still kept coming on by themselves. The ground connection at the frame was removed and cleaned and the brake switch was replaced with an OEM part as suggested by one of our techs. The vehicle had an electric brake controller on it when I purchased it, so I disconnected the controller. These changes brought no resolution. Next I replaced the cruise control stalk and turn signal switch. The stalk was OEM and the switch was ACDelco. Finally I replaced the flasher under the dash. That seemed to solve the problem, or so I thought. That is until now.
In the last year the headlights and taillights have been replaced with A/M units and a remote start has been added as well as a Kenwood head unit and new speakers. Since this same issue occurred when the vehicle was all stock with the exception of the brake controller when this happened previously, I figured the problem has to be somewhere in the factory components. My next step is to take apart the underhood electrical center and see if I see anything weird in there.

I didn't go into all of the details originally due to the length of the post.

 

[OR VietVet]

Long story but lots of needed details.

Have you tried the flasher again? Fixed it last time. What brand was the last flasher? Please tell me it was not a DORMAN.

 

[Rocket Man]

There's also a main wiring harness junction block under the passenger side rear that sometimes gets corroded. If you lay under the back of the truck and look up inside of the fender on that side you'll see it. You can pull it down, unplug everything and look for signs of trouble.