Parking Brake light on all the time....fluid in Master Reservoir is full

[4dr_vr4]

The Parking Brake light has decided to come on and stay on for reasons unknown. Brake lights go on and off. Brakes work fine and master is full.

Any ideas?

Thanks.

 

[Nebraska]

Maybe your parking brake switch took a sh*t. I’d have to check schematics but I believe that it is a normally open switch and when you pull the ebrake, the plunger releases as well and the contacts close. I’d imagine if it’s not broke, it’s stuck and can be physically corrected but when in doubt ohm it out.

 

[thomcasey]

There should also be a brake fluid level sensor connection at the master cylinder. I think it is either a 1-wire or two wire connection.

 

[Nebraska]

Here is the service manual schematic. I do not have my reservoir plugged in and my light does not come on. I guess you can use that as a troubleshooting tool though.
Good luck

-Garrett

 

[AllanL]

Check the rubber gasket under the cap of the fluid reservoir.

Shape should be like this:



If not, will make the dash brake light stay on always...just massage it to bring it back to this shape.

 

[Nebraska]

How would the diaphragm make the light come on?
Not saying you’re wrong by any means.

 

[fuel]

the diaphragm can poke out and push down the level sensor.

 

[FlyingEagle]

Ah, I was going to say that the Park brake light comes on when the alternator brushes/voltage is dipping because things are on the way out.