I have a hole/button may have been a button or **** at some point, on my dash. It's near ignition key/lights/wiper ****, to the left of that, in the corner of the dash. What is it? Anybody have a clue what I'm even talking about hahaha...

 

Brake System Warning Lamp hole.

I hope that the wire that should be connected to that is well insulated if it is tucked up under the dash. If the warning switch is active, that wire is hot.

 

Cool. Thanks. Been scratching my head on it for a while.

 

here are the pieces plus the light socket

 

Who ya calling a dashole?

.... I couldn't resist.

 

Ah yes it's Hot alright, it is wired into the main 20 amp fuse.
If that wire ever shorts or if the bulb is out and it touches ground the wire is to small of gauge to pop the fuse.

But it will turn red hot and burn up your dash wiring if not the whole truck.
It would be wise to add a 2amp fuse inline.
Orich

 

Funny thing; mine only lights when brake is set AND ignition @ "start". (?!)

 

Then sounds like the brake proportioning functioning correctly an is centered=ok.
Meaning it's not grounded like what happens when these trucks have brake failure and the proportioning valve is never reset and or it's stuck.

Most people don't know how to reset it or even service it and just remove the light or wait till it burns out. I have even seen black tape placed over it at PnP.

Anyway the light has power at all times, it's when the proportioning valve gets ground that's what causes it to power up the light when it's on at all times.

Also some people remove the ground connection on the proportioning valve itself that turns the light off.
Orich

 

On '68-up models (not '67), it's normal for the brake warning light to come on when you turn the key to the "start" position. This is part of the prove out circuit to the brake warning light to let the driver know the bulb is good.

When the key moves from the "start" position to the "run" position, the warning light should go off. If it stays on, you have brake hydraulic problems that needs to be addressed.

 

Just a heads up that Bumpside trucks don't have a (factory) proportioning valve.

All '67-'72 F100s came from the factory with 4-wheel drums and a pressure differential valve.

'68-'72 F250 & F350 trucks were available with optional front discs. Those trucks used the same style pressure differential valve as the all-wheel drum brake trucks. The only difference was the addition of a stand-alone metering (hold-off) valve that was mounted inline to the front disc brake circuit. --power brakes was optional on any of these trucks.

In '73, (manual) front disc brakes became standard on all the F100 through F350 4x2s. Power brakes was optional. There were 3 functions integrated into one valve body assemly: 1) Metering to control the front disc brake circuit. 2) Pressure Differential to sense for an imbalance between the front and rear hydraulic circuits and, 3) Proportioning to control the rate of pressure rise to the rear drums, after a predetermined pressure had been reached, to reduce the chances of the rear drums locking up during a panic stop.

Proportioning would only be used with a discs front/drums rear application and not on an all-wheel drum brake setup. But, as mentioned above, even '68 -'72 F250/350 trucks with optional front discs didn't even get a factory valve assembly with a proportioning function in it. Proportioning didn't become a function in the brake valve assemblies, on the factory disc/drum brake systems, until 1973.

 

Ultara
Yes, I am a ware that, later disc brakes have a P-valve as, I think about my vehicle when describing his parts and guessed, I should have asked what brake setup he had on it. Or, I could have just said the brake fluid distribution block would have cover the item all items of what ever was being used..

Orich

 

Anybody know the correct bulb number or a current equivalent?

 

None of my lights have ever worked

 

Industry number 1445.
Ford part number was B6A13466B.