I just got a '65 rust bucket with a utility bed (like the trucks the gas company uses with a bunch of lock boxes on the sides of the bed).

The guy I bought it from said the tail lights were on the bumper thats still in his shed (as we speak), and so I had four wires dangling from my rear end. Yellow, green, and two black ones (er mabey black and brown). The yellow and the green flash with the turn signals, and both the dark ones light up with the headlight switch. Anyways, I got two generic tail light kits from the autozone near me with one two-filament bulb (behind a red lens) and one single filament (behind a clear square lens). I picked one of the dark ones and wired it to one of the filaments in the double bulb on both sides and hooked up the two turn signal lines to the other filament. For some reason though, they stay brightly lit all the time and don't flash or turn off at all unless the headlights are switched off. I guess I got the filaments backwards? Is one brighter than the other ? Also, is there a backup light wire? I had figured that one of the wires back there was surely for the backup, but thats not true if they both light up with the headlights right? Also, once I get these wires switched around if I have to, are they going to light up with the brakes like my brake tag says they should? I didn't have any helpers today so I couldn't check on the brake light status.

Part two: The front turn signals work like they should except when the headlights are switched on. Then they don't come on at all. Same for the headlights themselves. Nothing. The dash works good though! All the lights on the dash come on and dim with the switch. Doesn't help me when it's 9:30 at night and I just finished switching out the fuel pump in the parking lot of the autozone. So tomorrow I think I'll pull the bright pedal and hotwire it to see what happens.

BTW this is my my first post and my first old school ford, but it's NOT my first beater, so I made sure to run clean grounds for all my new lights.

Any help is welcome!
-sam

 

Thats a 1965 f-250 3/4 ton with a 352 turning a 4-speed manual.

-sam

 

Sam, It takes three wires to run the tail lights.

1- is the shared tail light

2&3- are left and right blinking, that also share brake light duties

Don't have any idea what the 4th might be for.

John

 

What about the backup (the white one?)

 

Don't worry about the front parking lights not being on with the headlights - its supposed to be that way on these old trucks. As far as the wiring of the tail lights is concerned - BROWN is tail lights, GREEN is right turn/stop and YELLOW is left turn/stop. BLACK could be a ground wire.

 

Sam, There were no backups on the 65.

John

 

It is always possible that the wiring has been modified from original. Trailer wiring harnesses use white as a ground and a blue as an electric brake connection. I would map the wires like Jowilker and Jigsaw stated, verify correct signal without the new lights connected keeping in mind the circuit will not be complete without the bulb in the circuit. Lights off, Brake off, Left Turn on, check for power on Yellow. Lights off, Brake off, Right Turn on, check for power on Green. Parking lights only on, check for power on Brown. Just as another note to consider. My previous truck's brake lights were wired without the ignition switch in the circuit and this one has to have the key on for them to function. Also, the ignition will have to be on to test the turn signals.
One last note: If you wired the brown wire to each bulb as the ground then there's no telling what will happen when the parking lights or headlights are on because you now are feeding power back into the park and/or turn circuits

 

re:
Don't worry about the front parking lights not being on with the headlights - its supposed to be that way on these old trucks.

So I don't have any turn signals in the front when the headlights are supposed to be on? Also, are the headlights hooked up to a relay or do they run full current straight through the switch?

-sam

 

Sam, The park lights go off in the front when the head lights are turned on, and the signals do continue to work. The headlights are not on relays from the factory.

John

 

Alright, so here's what I did: I started by switching the wires to the double filament (1157) bulb. One of those filaments is brighter than the other and must be wired as the turn signal/brakelight. the other is the tail light. I have no backups, which I must say is no great loss. I still don't know what the other line is for, out of the four, but I do know that at this point I have tail lights and turn signals. Still no brakes or headlights yet. I read about someone else stomping on their high beam pedal so I did too and the headlights started working too. So I then hotwired the plug to always use the lows (I live in the city, so I don't ever use highs anyways). Alright now I got tails, turns, and lowbeams, with the option of getting a new switch to get highs too. So all I needed was the brakes. Quick trip to autozone, five bucks later and now I got brakelights. So I think I'm set here.

Thanks!
-sam