Idiot light on 1990 C-1500

[rubberhead]

I've just bought a beat up truck and as I was driving it there was a brake light in the lower right corner of the instrument panel that was on. I didn't have an owners manual, so I need to know what the light represents. I checked the emergency brake switch and it was working. It did appear that the light was brighter when the e-brake was depressed. Is the only purpose for the light is when the e-brake is engaged or is it a light to indicate a brake problem, like the abs or other?

Thanks for any advice

[mrjohnwayne]

If it were ABS there should be a light just for that.

[gmtech]

Ir you have rear wheel antilock brakes it uses the red brake light to indicate a problem. Those earlier systems were very basic and most people could not even tell if the system was working or not. I work at a dealer and should not say this but there is a black box about the size of an owners manual alongside your master cylinder that has 2 plugs on it if i remember correctly if you just unplug the box the start the vehicle and the light is out the problem is in the abs system. But then ofcourse if you want to get into it and fix it would need to reconnect it and drive it til the code sets again and have it diag. Or just leave it unplugged and take off the box and now you have normal brakes.

[rubberhead]

Originally Posted by gmtech

Ir you have rear wheel antilock brakes it uses the red brake light to indicate a problem. Those earlier systems were very basic and most people could not even tell if the system was working or not. I work at a dealer and should not say this but there is a black box about the size of an owners manual alongside your master cylinder that has 2 plugs on it if i remember correctly if you just unplug the box the start the vehicle and the light is out the problem is in the abs system. But then ofcourse if you want to get into it and fix it would need to reconnect it and drive it til the code sets again and have it diag. Or just leave it unplugged and take off the box and now you have normal brakes.

Yes, I have RWAL brakes and I have the black control module on the side of the master cylinder. I'll try your trick tomorrow..........thanks!

[rubberhead]

Originally Posted by gmtech

Ir you have rear wheel antilock brakes it uses the red brake light to indicate a problem. Those earlier systems were very basic and most people could not even tell if the system was working or not. I work at a dealer and should not say this but there is a black box about the size of an owners manual alongside your master cylinder that has 2 plugs on it if i remember correctly if you just unplug the box the start the vehicle and the light is out the problem is in the abs system. But then ofcourse if you want to get into it and fix it would need to reconnect it and drive it til the code sets again and have it diag. Or just leave it unplugged and take off the box and now you have normal brakes.

Well, I tried unhooking the cables, of course with my luck it didn't help. I was driving it the other day and if I slowly press the brakes the light goes out, then if I press it harder it comes back on. Is this not an ABS problem? I checked the brakes and they looked good, could it have a little air in the system?

[mudseeker]

air would cause a spongey petal, it would not set a code though. i think this is a comon problem for chevy. when i bought my truck the fuse for the abs was pulled and i have not reconnected for this reason. the abs on our fullsize chevy van also does not work right. wish i could help solve your problem though.

[smokensteve]

not sure if you found problem..But i had a 1990 k1500 with a similair problem...I reset the computer and it has worked fine since...not sure how to reset... I had a friend do it for me...but it did work