Mike
Can anybody help????
Recently brake lights stopped working. Fuses all OK bulbs all OK, is it a pressure switch on top of a ford master cylinder? Is there any way of
checking this?
Cheer's
A
Pull the wires off the switch and touch them together. Check one side has 12v first. If it works its the switch.
Doubt it's a brake light switch on the master cylinder , it's more likely to be a low brake fluid warning . Follow the brake pipes, your more likely to find the brake light switch, as said join the wires to test the brake lights. Brake light switch could also be mounted on the pedal box depending on type. You have checked the bulbs?
A Ford master cylinder would suggest a good chance of Ford pedals also. If that's the case they usually have a plunger switch which is operated by the brake pedal to operate the brake lights, it's usually adjustable by turning it a quarter turn then slide it one way or the other. Turn it back to lock it in position.
Problems get more interesting....
All bulbs look OK. Touch brake pedal one brake light comes on and the opposite rear side light comes on. Press the brake pedal harder and the lights
go out. Switch side lights on without touching brake pedal and rear lights work OK. I was thinking a short somewhere but the different pressure on the
brake pedal is confusing.
Bad Earth on the rear lights (the one that goes out) .corrosion in bulb holder or bulb issue .
[Edited on 5/3/16 by ian locostzx9rc2]
quote:looks like two separate problems, the first as Ian suggests is bad earth,
Originally posted by AlanH
Problems get more interesting....
All bulbs look OK. Touch brake pedal one brake light comes on and the opposite rear side light comes on. Press the brake pedal harder and the lights go out. Switch side lights on without touching brake pedal and rear lights work OK. I was thinking a short somewhere but the different pressure on the brake pedal is confusing.
Hi had this problem before and it was a brake light bulb incorrect or incorrectly fitted just a chance this is the problem.
Mike
Brake pressure switch found on the brake lines as rusty nuts suggested, poor connection solves brake light problem. Still got the anomaly of rear side light switching off when brake pedals pressed. Bulbs checked and all ok. Bad earth somewhere again as suggested. Solve that problem next weekend with luck.