Reaching my breaking point. I believe I have some electrical issues with my truck. The brake light comes on and off while driving (not blinking), the speedometer jumps all over the place, and randomly after the lights coming on and off the truck seems to not want to shift gears. It starts roaring and riding rough. Any ideas?

 

Rather than just the one word, 'Help', as a thread title, I have edited it to tell members why you are posting. It usually helps with getting replies.

 

With: "brake light comes on and off" to you intend the rear brake lights or the CHECK BRAKES light or the PARKING BRAKE light in the dash?

If i do correctly interpret you do not have an issue with your external lights but it's all related to the dash and behavior of the drivetrain electronics.

Could be an indication of a ground issue. Give us the details I'm sure someone else is jumping in soon.

 

Thank you 😊

 

Yes it's the parking brake light. The dash is where I see all the issues. Lights coming on then on after I take off.

 

Is it only the speedometer behaving that way or other gauges as well?

Starts to seem like a VSS isue. Could throw any kind of problems with shifting as the gearbox does no longer know at what speed it is. It could also mess up the TCC activation.

Now that we have narrowed it down we would need to know with what vehicle we are dealing:

Make: (Chevy, GMC, Olds)
Model: (Blazer, Jimmy, Bravada)
Year:
Transmission: (Auto i guess from the description)
2WD or 4WD