I have a 79 F250 that the signals quit working. I have no lights or flashing on either side. The four ways do work. I replaced the fuse and the flasher, but no change. Do the four ways and the signals use the same flasher? I only see one flasher. I also checked the wiring plug connection for steering wheel... looks fine. Any suggestions on where to look next would be appreciated.

 

No. Pull the flasher you found and see if the 4-ways work. If not, that must be the four way flasher. The little bit later models had a flasher on the front of the fuse box, and one on the rear of the fuse box.

 

It's not the flasher. I found the second one and changed it. Not sure where to go to next.

 

Do the brake lights work?

 

Just discovered I have no Brake lights either. Just the tail lights are working. No signals or brake lights anywhere.

 

It's looking like a problem with the turnsignal switch.

The signal from the brake switch and the signal from the flasher both go into the turnsignal switch. The turnsignal switch then co-ordinates the these two signals to the rear lights, since the turn and brake light uses the same filament in the bulb.

I would center the turnsignal switch, and then make sure you have voltage coming into the switch when the brake pedal is pushed. If you do have 12 volts going in, and none coming out on the rear light wires, then it is the turnswitch.

 

Still no signals, but I do have brake lights on the right side so... I removed the signal switch. I found a broken wire, but I can't see where it broke off from. My concern is the horn did not work, so could this be the cause of my signal problems, or is the wire the horn problem. The wire is green with a red stripe. Does anyone have a wiring diagram, or a pic of the back of a signal switch for a 79 f250 with a manual transmition? The saga continues.....

 

Well, if we assume the wire is old, and it is really lightgreen/orange instead of green/red, then that is the wire that goes to the rear left brake/turn light.

 

Thanks... that helps

 

Will the signal switch from a 79 F250 Automatic work on my 79 F250 Manual trans? Are the electrical plugs the same?

 

Don't know, but I bet they are the same. Go to partsamerica.com, and plug in your truck with a manual and see what part # comes up for the switch. Then back out and start over except plug in an automatic truck and see if it gives you the same part number as the manual. That should be the proof.

 

Sorry... I originally put this in the wrong forum by mistake..



I have replaced the signal switch (as suggested) on my 79 f250. I still have no signals. I have brake lights, tail lights and flashers. I have checked the fuses, and looked for any bad connections. When I turn on the signal I get absolutely nothing, either direction. Any other suggestions?

 

Of course you changed the flasher just because.
When you move the signal lever R or L, do the indicator lights in the dash light up? If not, I'd think that you're not getting power into the signal switch.
AL.

 

Look at this diagram at the bottom center. You will see a blue wire feeding the directional switch. Do you have power on this blue wire?

http://www.autozone.com/images/cds/g...3d800ce987.gif

 

Am I correct that the power comes from the Fuse box to the flasher and then to the Signal switch? I will trace it out tomarrow, but I think you are correct. I dont think I have power to the signal switch for the signals. If that's the case where do I look Next. I have changed the fuse.....

Thanks