Symptom: The both front turn signals are not working. At times one of them will work when I first start the car (I think in colder weather) but shortly after will stop working again. Headlights/hi-beams still work.
Research: I have checked for any visibly burnt bulbs and replaced them. I took it into the shop and they told me there was a short somewhere in the passenger headlight wiring loom (driver side decided to work for them) and that the input to the headlight was working properly. I ordered a new headlight which came with bulbs already in it and installed it but am having the same issue.
When using either turn signal it blinks fast and I have visually verified sure the rear bulbs are blinking and the front ones aren't. When they sporadically work I have not been able to stop the car and verify the front bulbs are blinking. Also when they sporadically work it only lasts about one full turn so I have not verified that when one works the other does. When I turn the hazards on only the rear bulbs work (so not relay?).
Question: In what order should I check/replace parts? I am fairly confident that it is not the bulbs or the relay that is bad and am unsure how to proceed.
Possible Cause: I had read on one site that it might possibly be an issue with a broken ground wire. When the auto shop tested the inputs into the headlight they may have simply tested the voltage coming in to make sure it was good and didn't check the ground. Do the turn signals have a separate ground wire than the headlights?
Update 1: I ended up taking the car into the shop as it is a previous salvage and it turns out there is some custom wiring (cheap repairs?) done. They found that the multi-function switch was causing bad voltages, and after I replaced it my right turn signal works again. Left still doesn't, but I am making progress!
Multi-function Switch Symptoms: The right front turn signal (caused by bad multi-function switch) not only didn't work, but the dashboard light also was incredibly faded (could only partially see at night). Not sure if the dashboard light is a good indicator of a bad switch, but it was specific to the right side.