brake light issue's 66 f100....pressure switch???wiring??

cj92345 · Post by **cj92345** » August 25, 2009, 5:41 pm

my truck has a little boggered up wiring i'am trying to fix, i have no brake
lights, put a new pressure switch on it.....i can apply power to one of the
wires and the brake lights work, is the other wire just 12v from the fuse
box? or key on power??...help..

thanks in advance
chris

Paul · Post by **Paul** » August 25, 2009, 6:06 pm

On my 64, the power for the brake lights is from a fuse on the bottom of
my light swich. It is always powered no matter the key position.

cj92345 · Post by **cj92345** » August 25, 2009, 6:29 pm

i think i figured it out,

we only have power when the key is on, maybe
someone changed it a some point....or thats how these trucks are wired, but i only
have brake lights when the key is on, which is ok with me, truck will
sit for a month at a time sometimes

Haus · Post by **Haus** » August 25, 2009, 7:40 pm

brake lights should be constant power. You can also add a bracket and an aftermarket plunger type brake light switch and eliminate the pressure type switch.

65 66 Ford · Post by **65 66 Ford** » August 25, 2009, 11:28 pm

The brake lights on a 65 and 66 only have power when the key is in the on position, if it is in the off position no power to lights. The brake lights are powered through the turn signal switch.

Von Dud · Post by **Von Dud** » August 27, 2009, 10:33 am

i agree with Fran - my 66 needs the key on for brake light power. drove me nuts after chasing related bugs around the system.

Custom Classic Trucks or Classic Trucks mag did a one pager tech article on replacing the pressure switch with an off the shelf NAPA plunger and home-made bracket at the pedal... can't remember the issue though. Will post if i can find the article.

Rod & Custom did an article using a fancy-pants mechanical switch: http://www.rodandcustommagazine.com/tec ... index.html made by these guys http://www.watsons-streetworks.com/brake_switches.html

good luck.

cdherman · Post by **cdherman** » August 27, 2009, 6:25 pm

In my gallery there is a pic of my former mounting for a plunger style switch.

[albumimg]782[/albumimg]

I made the braket to fit on the side of the steering tube. It was made of a 4" piece of 1 1/4" steel pipe that I sectioned to 1/3. I then welded a tab to the pipe that I had threaded with the correct threads for the plunger switch. You could just drill a hole through the tab, but then you would have to rely on the nuts on the plunger switch to adjust the positiion.

Under the underneath side, I put some felt and then I held it in place on the steering tube with a couple large hose clamps. Worked very well. You position the thing so that the brake arm compresses the plunger when the brake is al the way out, but as soon as you depress the brakes, even a little (and far earlier than with the pressure swtich) the brake lights come on.

I later had the whole dash appart doing my powersteering and automatic tranny upgrade. I discovered that the bumper arm that stops the brake pedal travel can also be used to depress the plunger. By drilling a new hole through the brake/clutch pedal housing from above (can only be done with the whole assembly removed from the truck), you can make the plunger switch disappear completely under the dash. Also works good, but not worth the trouble, unless you have the dash all apart and the brake/clutch pedal assembly removed already for some other reason.....

Post by **Greg D** » August 27, 2009, 6:47 pm

While you are at it ditch that unreliable single master cylinder and convert to a dual. Use a 68 Mustang MC on a straight axle truck and a 70 F 100 MC on a Twin I.

65 66 Ford · Post by **65 66 Ford** » August 27, 2009, 9:54 pm

Greg D wrote:While you are at it ditch that unreliable single master cylinder and convert to a dual. Use a 68 Mustang MC on a straight axle truck and a 70 F 100 MC on a Twin I.

The 70 F 100 MC willnot work the rod is too long. You can use an MC for a 67 F 100 it has the correct length rod for the 65 and 66 F 100. If you want power brakes get a booster MC setup for a 67 F 100 and a set of mounting brackets from a 65 to 72 F 100.