So the hazard lights flash front and back. The brake running lights work when I turn them on, but I get no light when I press the brakes in. I have replaced the brake light switch already. My brake light switch is the same off of a 73 f250. It's not the original 2 prong deal. I can't seem to find a relay or a fuseable link that could be out somewhere. Any help or fingers pointed to the right direction would be greatly appreciated.

 

1940/66 FoMoCo vehicles use a pressure activated brake lamp switch.

1967/79 F100/350: Adjustable brake lamp switch attaches to bracket on brake pedal. 1967 is one year only.

 

Here's my setup. I purchased the truck like this. Everything was working when I purchased the truck. The signals weren't working all that well but they did work. The issue started after the wire from the starter to the solenoid shorted and fried the voltage regulator. All that has been replaced. I just can't seem to find the issue

 

I would get out your voltmeter and see what you have for voltage between ground - find a good shiny spot without paint - and one of those two wires at a time on the back of the brake light switch you have inside. Both with and without the pedal depressed. I assume this is a "break on contact" type of switch so nothing flows when the pedal is in its upward most position - farthest from the floor board.

If you have voltage on one side without touching the pedal and on both sides when pushing on the pedal - then trace downstream from the side that only has power when pushing on the pedal.

I hope that makes sense.

Chad

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That makes complete sense. I'll have to test it out when I get off work! Thanks chad.

Zach

 

Brake lights and turn signals not working. Fuses appear to be OK. Headlights, taillights, instrument panel work. Replace brake light switch first?

 

My brake lights and turn signals not working. Fuses appear to be OK. Headlights, taillights, instrument panel work. Replace brake light switch first?