I need some help y’all! Alright so I installed a painless wiring harness for my 1977 F-250 Custom and we’re having trouble with the brakes so I used the brake switch painless gave me and it was backwards so I went to autozone and bought a new one same thing happened so I went to oreily and got another one and same thing so I’m confused what’s going on it’s a step side truck so I bought trailer lights so idk if it’s the lights or what and I did check to see if the wires were correctly and they are

 

What do you mean by backwards? Do you have a picture?

 

so when you press in the brake switch the lights should turn on and when you let go the lights turn off well I’m experiencing the opposite when you plug the brake switch in the lights immediately turn on and a straight 12v go to the lights and when you press the switch they turn off

 

That is how it is supposed to work...the brake pedal hold the switch in until you press the brakes...

 

Without pressing the brakes the lights are on and when you press the brake the lights are off

 

Post up a picture of the switch and let us have a look. A shot of the wires running to it also.

 

I will tomorrow around 5pm central time

 

I found your other thread, and you got some bad advice there. The brake switch is considered normally closed. Your other thread also said when you press in on the switch, the brake lights go off...this is normal, as-designed behavior. The switch gets adjusted up against the brake pedal lever to hold the switch in (turning the brakes off) until you press the break pedal...which returns the switch to it's normally closed state, turning on the brake lights...

 

There are plunger type brake switches that work opposite of each other, and they have different mounting scenarios. One mounts above the pedal and as the plunger extends when you push the pedal down, closes the switch. The other mounts below the pedal and as you push you compress the plunger, turning on the lights. Sounds like you have the latter, but mounted above the pedal, so you just need to find one that works in extension.
If you are buying switches for your truck and they don't match what you have, then either someone in the past changed yours out to a different mounting configuration, or Ford did.
I've seen them both ways and have bought both types of switch.

Definitely post up a pic when you get the chance and we'll compare to what ours look like. But since there are two types, rather than re-orient yours to work with the existing switches, it seems to me it would be better to find one that works the opposite of yours. Even if it happens that you have to source one from a mid-seventies Chevy truck for the parts guys to find the right one.
What is your truck specifically too. Is it a standard or SuperCab? Is it a single or dual rear wheel (did they even make 250 duallies, or was that only for the 350's?), standard rating or Camper Special? Something else odd about yours maybe?
Don't know if any of that would change the pedal configuration, but hey, Ford did some strange "variations on the theme" back then. Didn't know 150's came with leaf springs in front until I saw my first SuperCab. Had only seen once before a dual charcoal canister setup until someone just posted up a few days ago their 350's twin setup. NumberDummy has said many times that there was something like 19 (or 54 or a million!) different brake pedal/booster/master combinations on our trucks!
Maybe one of those included a backwards mounted light switch?

Is there by any chance a second switch for cruise-control that looks the same? If so maybe that's what they're giving you at the counter.

Paul

 

So I was confusing myself but it was right this whole time so when I plugged in my brake switch we were testing lights so it wasn’t mounted to the brake pedal that’s why I was confused I thought when you press the brake the switch closes and then etc but now when it’s installed in my pedal it works just fine thank you for everyone’s help!