I've got a stumper

[Chevy305]

Ok so the other day my brake idiot light came on dimly while manuvering around the driveway. Then when I pressed the brake pedal the radio got staticy but the brake pedal felt completely normal. So I shut the truck off and did a thourough inspection of the whole brake system to find no leaks and my brake fluid level has never changed. I started the truck back up and no brake light. Today I go to drive it and the brake light is on at full brightness all the time but no radio static. Brake pedal still feels great. I can pump it up and it holds firm and still no system leaks anywhere. Anyone have any insite on this?

And no my parking brake is not on...

 

[cuervo]

Ok so the other day my brake idiot light came on dimly while manuvering around the driveway. Then when I pressed the brake pedal the radio got staticy but the brake pedal felt completely normal. So I shut the truck off and did a thourough inspection of the whole brake system to find no leaks and my brake fluid level has never changed. I started the truck back up and no brake light. Today I go to drive it and the brake light is on at full brightness all the time but no radio static. Brake pedal still feels great. I can pump it up and it holds firm and still no system leaks anywhere. Anyone have any insite on this?

And no my parking brake is not on...

Dirty connection at the wire on the brakes? Switch going bad?

 

[fabjunkie]

Sounds like a loose ground. Does it share a ground with the radio?

 

[blazinzuk]

Sounds like a loose ground. Does it share a ground with the radio?

It really seams like most weird problems like this can be traced to a bad ground somewhere

 

[79rustyk10]

What truck?

 

[Chevy305]

What truck?

The K10

I do believe the radio and the light is grounded separately. Can't remember for sure, I will take a look at it.

 

[79rustyk10]

I would have to say a ground issue, but I had a issue on my 89 k2500 where the brake light was on, turned out a wheel cylinder was leaking enough to loose fluid, but not for me to notice in the pedal.

 

[1-ton]

It could be a hot wire somewhere which is grounding out, and supplying power to circuits it shouldn't. Also, if you have a brake dummy light it should be connected to some type of sender unit, which triggers the light to turn on when it detects low fluid level. If this sender has gone bad it could be the problem.

 

[dremu]

The brake light is connected to two things.

One is the combination valve (aka proportioning valve.) It will come on if there's a large difference in pressure between the front and rear circuits, generally indicative of a leak or low fluid. It sounds like you've covered these.

The other is the parking brake. Since you mention the radio, I'm inclined to suspect that the problem is the switch on the parking brake lever assembly and/or the wiring to it, i.e. up under the dash. I'd start at the connector to the switch and work your way up into the dash.

-- A