I recently got a 1978 F100 Custom. it is in pretty good condition. My turn signals and headlights are working but i have no hazards or brake lights. I have a multimeter but have not tested lines yet. I did hook trailer lights up to the plug and the brake lights didnt work on them either. Would this point to the thing on the brake pedal? Is there a seperate fuse for hazards and brake lights, i cant read the fuse panel. Are the brakes ran through the headlight switch? Schematics? Any Help would be greatly appreciated.

 

Welcome to FTZ.
1, brake and signal lights us the same bulbs n 2 wires for the rear of the truck. There are 2 wires, one for each front signal light. All those wires go thru the signal light switch. So you know they work, bulbs and wireing.

2, The thingy on brake pedal is the brake light switch. Some vehicles might require ignition switch to be on for brake/stop lights to work.
Two tests,
1, With multi meter in the 20V position, remove the 2 wires from brake light switch, hook multi meter black to ground to good metal. Ign key on to run, probe the 2 wire terminal openings for one to have battery voltage, if none in either, check the brake fuse. SOMETIMES fuse good but rust has accumulated on the metal fuse holder clips, try to clean somehow.
2, IF there is power to the brake switch wire, take a small cotter pin or paper clip and jump the two wire terminals together and see if you have brake lights, yes, bad brake light switch.
There may be a second Flasher for the Hazards if you find try swap with signal light flasher that you know works.
Stop and Hazard may have separate fuse's. If your fuse block not legible ??
You can Google, wire schematic's for your particular truck, many out there free, and get clean picture of your fuse block so you can see what fuses are for what

Let us know how you make out, Cap

 

I took the multimeter and tested the brake light switch and it read zero volts on both wires. I moved on to the fuse box checking the bottom side of every tube fuse. The 20A EMERGENCY fuse was blown. I replaced, and now Hazards, Tailights, and Brake lights are all working. I never suspected that the brake lights would be in that line, I don't know why, looking back it makes sense. Thanks Cap! Now i can drive it with out worrying about a ticket. You gave me a lot of knowledge for in the future!!!

 

Just Love a happy ending! Glad to help out. If any projects or updates to your truck, please share with us, we like to tag along. And did I say.......We like pictures

 

I am very sorry for the lengthy response in a picture. This is first day I had a chance to get to my desktop, I have been trying from my phone but picture was too large, and i couldn't reduce on phone. So here is Ol' Blue.

#ad

 

Cool, thanks for the pic. Ol'Blue gonna be a work truck or a fix up a bit, fun driver?

 

She's gonna be both really. At the age of 14 i always wanted to do full restorations, but seeing that i still don't know how to weld that isn't happened thus far. So for the time being she will be a fun driving work truck, rough around the edges with a strong heart.

 

Great! Have fun!