So I had been having some trouble with the brake lights and blinkers on my 77 F250. I replaced the flasher fuses, standard fuses, and turn signal switch. I was still having trouble, so I ended up switching one wire in the pigtail at the rear lights. That gave me back brake lights and turn signals, but when I step on the brakes, the left rear blinker does not blink, right side still blinks when brake is depressed. I also no longer have front left turn signal at all. Any ideas?

 

You need to get back in the steering column. I hope you have a meter or testlight. You will probably need a diagram also. I will give you a brief overview of how it's hooked up, and maybe you can go from there.

You have two inputs to the turnsignal switch. One is the brakelight signal from the brake pedal switch, and the other is the flasher signal.

There are two general sections to the switch. One section does the front turn signals and the signals in the dash. It's a simple single pole double throw switch. Common is the flasher signal coming in, and the switch selects the left signal wire or the right signal wire. Each wire has a splice which turns it into 2 wires. One goes to the front turn lights and the other goes to the dash indicator light.

The other section of the switch is more complex. It does the rear brake/turn lights. Notice I said "brake/turn". The lights in the rear have a dual function in the brighter filament. When the turnsignal switch is in the center position, it puts the brake switch input on both wires going to the rear. When you move the lever to the right or the left, it lifts the brake signal wire off the correct wire going to the rear, and puts that wire onto the flasher input wire.