Baffling Electrical Question - Brake Lights

banjopicker66 · Post by **banjopicker66** » September 11, 2011, 8:37 pm

I know electrical. I know how to read schematics - well, at least the kind our trucks have.
I.
Am.
Baffled.

Symptom: I noticed the brake lights do not work with the ignition OFF. I thought they did a long time ago, though. (They work fine with the key on.)

About 2 years ago, I replaced the '66 steering column with a '72. I put in a new replacement switch - for a '72, I think. I don't remember. Everything works properly except the brake lights when the key is OFF.

So to troubleshoot all this, I get out schematics to find how power is applied to the brakes.
All along, I have believed when others have said that the brake switch is powered through the turn signal switch.
Schematics say otherwise.
Tracing the wires says otherwise too.
Power is supplied to the flasher and the brake switch from a fused and switch circuit off the fusebox - not through the turn signal switch, at least as far as I can see.
Am I wrong?
Do the brake lights come on when the key is OFF?

If so, what wire supplies power to the brake switch for the brake lights?

Thanks for any and all help.

banjopicker66 · Post by **banjopicker66** » September 11, 2011, 8:49 pm

And maybe I used the wrong switch?

slick4x4 · Post by **slick4x4** » September 11, 2011, 11:16 pm

on my 61 key has to be on for the brake lights to work
99.9% sure it is factory wiring

ezernut9mm · Post by **ezernut9mm** » September 11, 2011, 11:34 pm

the brake lights on my 67 don't work with the key off either. i always thought they were supposed to.

65fordguy · Post by **65fordguy** » September 11, 2011, 11:56 pm

mine only work with key on... I too was baffled at this.. but hey.. as long as they work with the key on!

3ontree66 · Post by **3ontree66** » September 12, 2011, 2:41 am

Ditto on my 66. Tried to troubleshoot for days thinking they should come on without the key switched on. It's the first vehicle I've owned like that. BUT, as long as they work, I'm happy

banjopicker66 · Post by **banjopicker66** » September 12, 2011, 6:40 am

MOST excellent. That they do not come on when the key is OFF is reassuring, and confirms my findings.

Thanks to each of you very much for your help!

Shadow · Post by **Shadow** » September 14, 2011, 8:33 am

The Brake Lights Work On My 64' Without The Key On.....

turtle1056 · Post by **turtle1056** » September 14, 2011, 8:58 am

having just wired my truck with the American Autowire setup i can tell you that a singe live power wire from the fuse box, not keyed power, supplies both the brake switch and the courtesy lights in parralel so that both can work when the key is off

the confusing part is that it is switched ground that makes them work, not switched power

I hope this helps

Fanatic · Post by **Fanatic** » September 14, 2011, 5:20 pm

John, my headlights won't work without the key on.......................

Oh yeah, I wired them that way on purpose LOL

charliemccraney · Post by **charliemccraney** » September 14, 2011, 9:16 pm

My brakelights work with the key off. The '61 schematic definitely shows the brake power going through the turn switch first.

Baffling Electrical Question - Brake Lights

Baffling Electrical Question - Brake Lights

"Brake Lights"