So here's a recap of events. Yesterday, I painted my trucks frame, gas tanks, and rusty floor pans with POR15. I did paint the bracket next to the frame where the parking brake cable connects to. I also had the passenger rear tire off for a brake inspection but did not mess with the parking brake. I didn't see any electrical connection for the light anywhere near where I was painting. Now the light stays on whether I have the brake engaged or not. The brake is working fine. Ideas? Thanks. The light worked before yesterday
My name is JP. This is the story of me and my truck.
1990 F-150 5.0 4x4- "Ginger"
Brake warning can come from 2 places. There's a limit switch at the parkin brake pedal and a level switch at the master cylinder reservoir. Disconnect the plugs on both of these, and the light should be out. Now connect one of them, if the light is on you found the problem.
Light on with just the brake reservoir switch connected = low brake fluid or switch is stuck.
Light on with just the switch at the park brake connected = park brake not released fully or switch is stuck.
Also, the switch that is on the parking brake works by grounding out the line. If that line got trapped anywhere and grounded out, that would result in a false reading.
I just pulled my switch and cleaned the surfaces last week - I had the opposite problem. My brake light wouldn't light when the parking brakes were set and unlike my smaller newer cars, the truck can overpower the rear brakes.
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