I’m having an issue with my turn signals and brake lights.

Neither of them work however my hazards work and also my rear lights stay on when I pull the hazard button out.

I checked all the fuses inside the cab and ordered an turn signal switch to see if maybe that’s the issue

1990 D250

 

We had a similar issue with a headlight and turn signal. It was old brittle wiring.

 

Remember... that power for all lighting goes through the headlight switch.
When I purchased my 89 it had no dash, interior, or tail lights. I just installed new headlight switch and everything worked... save one burnt out bulb.