BearKiller

Before I take the instrument panel off for the umpteenth time, what can cause the "BRAKE" light to stay on all the time the ignition switch is on??

This is on the son's 90 model.

I completely removed the wire on the switch at the park-brake pedal, no change.

I can, though, touch that wire to a ground and the "BRAKE" light will get lots brighter.

Please help.

Thanks.

DanMan

I have no clue myself, I've had mine for a little over two months and for more than a month the BRAKE and ANTI-LOCK lights came on and stayed on. Then, a few weeks ago we loaded up Dad's pick-up camper for a little vacation. Before we got back they had went out and haven't come back on since!

KB440

Mine stayed on all the time when the fuse blow to the brake light. Might be worth a shot to check the fuse.

BearKiller

That would also knock the brake-lights, wouldn't it??

That sounds easy enough.

I will step on the pedal and see if they light up.

Thanks.

EDIT/UPDATE

Too easy for me.

I just ran out and mashed the pedal; the brake-lights lit up like a Christmas-tree.

Now what??

torquefan

Unplug the connector from the "low vacuum" switch. It's located under the hood by the driver side hood hinge. If the brake light goes out, you have a bad switch or a low vacuum condition.

BearKiller

That would be that gizmo with the vacuum-line from the brake-booster locale, going straight to it.

I just spotted that outfit, this evening and figured that was what it was.

I will check it out in daylight hours.

Thanks.

Bookshelf

Is the ABS light on also? I had a problem with a truck one time where the lights in the information center were doing some funny stuff. I checked out the diagram in the factory service manual and figured out one of the diodes(only let current travel one way) was bad. Swapped in another information center and everything was fine. If the ABS light is on also, check the ABS codes, probably a loose connector where it plugs into the rear diff.

BearKiller

No, only the "BRAKE" light.

I haven't had a chance to check the vacuum switch.

Thanks.

kellypckp

When my ABS would come on I would unplug it from the computer(behind the glove box) and leave it off for a minute and repug.

I don't remember where I read it but it has something to do with how hard you applied the brakes and the abs activiting. I don't remember all the details. Sorry

It happen on my 90 and 91.

BearKiller

I un-plugged the connector and still had the light on.


I had the panel off and un-plugged that round pin-connector that powers all the warning lights, then plugged it back in, when I put it all back together.

I was real careful to orient that plug the right way.

While I had the panel in the shop, I used the model-train 12V power-pack to check all the bulbs and all five worked.

Could I have messed something up, when I removed/replaced the panel??

Thanks.

Jim5870

I had the brake light and ABS light stay on for a while, I disconnected the battery for 5 minuites or so and reconnected. The lights went out.

leper

If you apply the emergency brake, does the light get brighter? If not, the switch may be your problem. One thing you can do is to push the switch in and let it "snap" back out. Do you know what I am saying? Do this a few times and see if the light goes out. I also read somewhere about a bad ground for the ebrake causing problems.

BearKiller

I can un-hook the wire at the park-brake pedal and the light still stay on.

I can touch that wire end to ground, and the light will get noticably brighter.

By snapping the switch, do you mean the switch on the park-brake pedal??

Am I correct in thinking that the wire to the park-brake pedal is a GROUND from the light; and, instead of making the positive circuit to the light, it makes the ground circuit ??

torquefan

Yep, that's correct. If unplugging the low vac switch nor the park-brake switch didn't turn it off, the next thing to try is to unplug the pressure differential switch on the proportioning valve. I can't remember where it's located on 1st gens, probably right close to the master cylinder, if not, follow the lines down to the frame rail. Should be a single wire connector. If unplugging it makes the light go out, it may be a failed switch or a real pressure differential problem.