Odd brake issue!

[PoorManQ45]

I need a little advice guys.

My brother has an '05 GMC Sierra 1500. The Brake light on the dashboard is lit when the vehicle is off. No key in the ignition.

It flickers sometimes. Sometimes it's solid.

The brakes were bled three months ago, but the issue just started happening.

There is no issue with the way the pedal feels or the stopping power of the vehicle.

We have tried bleeding the brakes again. No change. Tapping on the electrical connections under the dash, in the engine bay, and on the ABS does not seem to affect the light flickering/solid.

Any help would be much appreciated.

Thank you

-Brien

[costa_rican13]

low fluid in the resevoir? if its full then by all means disregard this post.

[Mr1der]

crappy GM product?

if it's not having any effect on the way the truck drives, I wouldn't worry about it

hell, my mom's '03 Silverado doesn't have a functioning tack already...if it does read, it's usually damn near redline.

[Dattebayo]

The "negative ground" is probably shorted to the frame/unibody somewhere on the bulb harness. That, or the brake light switch on the e-brake handle is stuck closed.

[PoorManQ45]

The "negative ground" is probably shorted to the frame/unibody somewhere on the bulb harness. That, or the brake light switch on the e-brake handle is stuck closed.

I'll check all the grounds.

Why would the light be on with the key not in the ignition? That's what is throwing me for a loop.

[Bubba1]

low fluid in the resevoir? if its full then by all means disregard this post.

That was my first thought too, but he noted the light was on when the ignition was off.
Sounds like a loose wire somewhere. Not unusual for GMC. (The e brake light has never worked in my GMC You could always remove the bulb.

[Dattebayo]

The "negative ground" is probably shorted to the frame/unibody somewhere on the bulb harness. That, or the brake light switch on the e-brake handle is stuck closed.

I'll check all the grounds.

Why would the light be on with the key not in the ignition? That's what is throwing me for a loop.

Well TBH, I don't know if the car is negative switched or positive.

[xekushnr]

Well the only way it would work was if it was shorting somewhere. The problem seems to be in the light, not the brakes. Get a wiring diagram, chase the wire and find where the break is. Or save yourself some frustration and just run a new wire.

[PoorManQ45]

Well the only way it would work was if it was shorting somewhere. The problem seems to be in the light, not the brakes. Get a wiring diagram, chase the wire and find where the break is. Or save yourself some frustration and just run a new wire.

I was thinking that.

Unfortunately the light is a surface mounted LED. The entire gauge cluster is one large circuit board. So the entire thing will have to be replaced. It's not difficult, but it really sucks to have to do that for such an issue...

[alms24sebring]

The only thing it could be is the switch for the ebrake is stuck, or the brake fluid sensor is bad. I would check for brake code just to make sure, but a good scanner mite tell you if its one if the 2 staying on. It could be a short in the dash but unlikely.

[Dattebayo]

The only thing it could be is the switch for the ebrake is stuck, or the brake fluid sensor is bad. I would check for brake code just to make sure, but a good scanner mite tell you if its one if the 2 staying on. It could be a short in the dash but unlikely.

No, because you didn't read that the light is on when the car is off, key out of ignition also. I made the same mistake earlier in the thread... It has to be a short direct to the battery.

[Jesda]

A small LED wont drain the battery to a point where it wont start. Nothing a piece of electrical tape over the light cant fix.

[Dattebayo]

Does the car have brake sensors?

[PoorManQ45]

Does the car have brake sensors?

I'm not sure what you mean.

It does have ABS and sensors for that, but there is a dedicated ABS light.

The code reader at Autozone shows no codes currently showing, or in memory.

I'm leaning towards a short.

@Jesda: That's what I'm thinking...

[alms24sebring]

I guess thats true. I stand corrected by Bayo

The dash is sounding more suspicous