Hi All, I am having no brake lights on my 66 F100. I have replaced the Master cylinder and brake light switch, The fuse and the taillights. But still no lights I have park lightsbut when you step on the breaks.....Nothing nada zip!

So I'm outa Ideas, and need some pointers To point me in the right direction. Thanks.

 

Do the rear turnsignals work? The reason I ask, is the rear turnsignals and the brake lights are the same filament in the bulb, as well as the same wiring from the turnsignal switch all the way to the rear.

If the turnsignals work, then I would suspect a problem in the steering column or the turnsignal switch itself. The power from the brakelight pressure switch leads to and goes through the turnsignal switch.

 

Thanks Dave, No turn signals either I was going to address that later, I have a 65 F100 and brake lights work and the turns do not? Man I wish I had a Book!to show where the wires goes. Can someone help with a diagram?

I hate Electrical! Took me 6 months to figure out the not running thing, Stupid Mallory Unilight was bad like everyone said!

A bit more Info: the truck had 3 different trailer light plugs in the back and I removed all of them. I'm sure I have it back together right cause all the colors match.

 

This one should be close. it is of a 1964.

 

See if I got this right. These old diagrams are hard to read, even if they are large. See if you have a red, and a red/black going to your brake switch. If you do, the red/black should go to the steering column, and in the turnsignal switch. If I have the colors wrong, then get a testlight or meter, and put it on the brake pressure switch. One wire should have power all the time, and the other wire should have power only when you press the brake. This is the one that goes to the turnsignal switch, so make a note of the color.

I can't make out the wire colors to the rear bulbs, but you can quickly figure this out. Go back to the rear bulbs. On the brakelight bulbs you should have a common wire to both left and right. I believe this may be brown. This is the running lights, and we are not concerned with them. The other wire left is a colored wire. There should be a different colored wire for the left and for the right. Write these down, and you should find these same colored wires coming out of the turnsignal switch.

So, you should have a colored wire coming from the brake switch going into the turnsignal switch, and you should know the two colored wires coming out of the turnsignal switch going to the rear. Make sure the turnsignal switch is centered. Get a testlight or voltmeter. Find the wire coming from the brake switch going into the turnsignal switch. Press down on the brake pedal, and you should have power on this wire going into the turnsignal switch.

While holding the brake pedal down, measure the voltage of the two colored wires coming out of the turnsignal switch going to the rear. They both should have 12 volts with the switch centered. If they don't, and you have voltage coming in from the brake switch, then your turnsignal switch is bad.

P.S. While you are doing all this wire testing and digging around, I would recommend you take the battery loose, and hook a small battery charger to the battery cables. This way if something bad happens and a wire shorts out, it will trip the circuit breaker in the charger, and not burn up any of your wiring.

 

You Guys are the BEST! I will try to figure out and get back to ya later. Thanks

 

Maybe these will help:





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Knowing that the Hot wire goes through the turn signal switch was a BIG help. Thank's This is what I found

 

I have brake lights and Blinkers.... Imagine that, Now I don't have to worry bout someone Plowing into me!