I'm rewiring behind the dash to connect up the '91 tilt column in my '90 truck and I've come across a strange problem. The right rear turn signal works via the blinker switch, but not via the hazard switch. The other three turn signals all work via both.

Any ideas?

 

Possible burnt out terminal in the 4 way section of the switch.

 

My weird light problems turned out to be all sorts of greasy crud in the blinker switch, plus there's these little springs that push the contacts in the two plates against each other that had gotten knocked out of position. I'd bet you anything it's that!

 

Mine's weirder than that ---
Turn signals and hazard flashers worked as they are supposed to.
Replaced the stop/running lights in the rear with 1157 replacement LED's. Turn signals and hazard flashers still worked.
Added LED stop/turn signals to bed topper. Turn signals and hazard flashers still worked.
Replaced FRONT running/turn lights with individual LED markers - due to size constraints I used 2 lights, 1 for running and 1 for turn. Hazard flashers still worked, running lights worked, turn signal worked - but if I turned ON the running lights - park lights - the turn signal stopped. They went out and would not flash.
I tried replacing the individual lights with an 1157 replacement LED like in the rear and it also will not work...

I understand that the flasher requires xx amount of current through it to operate, so I bought an electronic flasher and it will not work either.

Ideas ???

 

Yes. The side marker lights ground through the front signal lights (that's how you get the alternating flash). The resistance of the LED lights is too high, so it's like there's no ground.