68 F100, No Turn Signals

[lightfoot]

Started my 68 F100 for the first time this year and have no directional signals. A few years ago, I had this issue but fixed it with a new Novita Technologies 12.5 Amp 2 Terminal Turn Signal Flasher - LL552. The 4-way flasher works fine but it's on a separate fuse. I switched the 4-way to the directionals (it's the same heavy-duty flasher) to see if the directional flasher failed but it didn't. Is there another fuse for the directional signals somewhere???
If not, does anyone have any suggestions on what the issue may be?
Thanks,
​​​​​​​Glenn

[cep62]

http://www.fordification.com/tech/schematics_i.htm
http://www.fordification.com/tech/schematics_h.htm
maybe you can find some info from these links. ?
Do the brake lights work ? if so does one go out when you pull on the turn signal lever ?
I've seen poor connections from the turn signal switch after sitting .
My old plow truck (77) usually needs a little working after sitting all summer.
You may try pulling the steering wheel and hosing the t s switch down with electrical cleaner.
I assume you checked for power going to it.

[zgerbic]

This era for Ford turn signal switches are the worst. Sometimes you need to wiggle the signal lever to get the turn signals to work due to the flimsy plastic switch design.

The turn signals are on a different circuit from the four way flashers. Also the four way flasher requires more current to flash than the regular flasher so it is not a good test to try the four way flasher in the two way flasher position. Bad grounds on the lights will keep the signals from flashing but usually you will see this on one side or the other but not both sides going bad at the same time.

First check the fuses. Then check that all the lights flash if the four way flasher is turned on. Next check if the brake lights come on when you press the brakes. I would next pull the dash panel out and make sure the big molex plug is making contact by unplugging and plugging it back in. Next is to turn on the ignition switch and measure the voltage on either side of the flasher. One side should have 12V and the other may have 12V or a little less. Move the turn signal switch to either side to see if it now starts flashing. If so, it was probably a bad connector or contacts on the flasher. If the flasher does not have about 12V on both sides then the power to the flasher is the problem. If the flasher has power on only one side but not the other then the flasher is bad. If the flasher is ok then remove the connector from the flasher and jumper the contacts on the connector and try the turn signals again (the lights don't flash but come on steady). If they work then the flasher is bad. If the connector now has 12V and the lights don't come on steady when the turn signals are turned on (flasher is bypassed by the jumper to provide 12V directly to the turn signal switch), then the turn signal switch is bad.

Before changing the turn signal switch, double check the switch connections at the steering column to make sure they are making good contact.