just got my 72 f250 with the 300 6 back together after a paint job and am now trying to work out some kinks.

I rewired all the wiring for the tail lights after pulling out a birds nest of wiring from the previous owner. I was able to get all the lights working other then the brake lights, I bought a new brake light switch and installed it and it fixed the problem.. or so I thought.

the original problem with the brake lights was that I had power to one side of the switch, and when I would press the brake pedal I would lose that power to the switch, and not have any power coming out of the other side of the switch to the lights, the weird thing was this only happened if I had the taillight bulbs in, if I removed them the switch seemed to work Fine.
After installing the new switch my brake lights worked fine for a day, but now the switch is doing the same thing as the old one was before, could this be a ground issue? Or some sort of shorting issue?

The problem with my blinker is different, the taillight blinker seems to work fine when I don't have my headlights on, but when I turn the headlights on the left blinker won't blink anymore (right one still does) and the left taillight goes out completely when the signal is on, but goes back on when the signal is off, (right one still works fine, and blinkers work fine without headlights on other then a burnt out bulb for the left blinker in the dash)

any ideas?

Another problem that maybe I should mention is that my front left signal/running light blows the filament for the running light as soon as I turn the running lights on with the bulb in, but the blinker filament seems to work fine

any electrical geniuses that can help me out with this madness?

Thanks jn advance!!!

 

Bump .......

 

I think you have some ground problems now that it has fresh paint. That left front bulb is trying to ground out more than just itself. Remove all 4 lamp ground wires and get through the new paint and give them a good ground. If the firewall was painted do the same thing for the engine to firewall ground cable. If the dash was painted without the cluster in there that cluster's ground wire's connection should be cleaned up as well.

 

Thanks Jeff I will look into the grounds for sure,

today I was able to fix the brake lights by running a wire straight off the battery to the hot side of the brake light switch (I put an inline fuse in) and they now work. After fixing the brake light problem all my blinkers and the 4 ways now all work with the headlights both on and off.

I will tackle the left front marker light blowing the bulb problem tomorrow

i now have a new problem that has come up, all but one of my dash lights won't work when I turn on the running lights/headlights. The only one that lights up is my left blinker light on the dash, which is weird because I don't think it should be illuminating at all times when I turn on the headlights?
again I'll take a look at all the grounds tomorrow and see if I get anywhere