1972 Kenworth W900A turn signal issue

Doe’s it have the Signal-Stat 902 on the column and head light dimmer on floor like oe or did someone monkey in a new style turn/dimmer switch on column?

 

Those switches ground to steering column through their body mount and strap. They require a 3 prong flasher. The center prong is the “pilot” to power and flash the light bulb in the switch. One for 12v constant battery power. And the other is for the flash signal to switch. If it works on one side then flasher is good. It doesn’t know what side is what. The switch itself is what determines direction the flasher signal goes. If that stuff is good i’d check to make sure the lolly pop light on front fender has good ground. The body itself has to ground through its mounting stud. Fiberglass hoods make this diffecult. You may have to run a dedicated ground wire along the light harness from the 1/2” threaded light mount to the frame or radiator support.

 

If were the wires going to the flasher are individual and have no harness plug any more you can use a replacement plug or a salvage plug from a high/low beam headlight socket. They are the same exact spread.

 

make sure your front bulbs are good. the LEDS won't pull enough juice to make the flasher work.

 

I'd have to think on a 1972 anything, the turn signals will be the least of your worries.

 

So the right side turn signals don’t flash but the left side does? And the right rear light gets bright (but no flash) with flasher in right turn position but right front does nothing?

Take a test light and check for power on the contact of the right front signal, have to remove the bulb of course. Make sure you have a good ground and don’t short the test light out bumping the metal bulb holder. It may be as simple as a bad round or broken wire. But need to confirm you have no power to right front light first….