turn signals inop

[1990idi]

just as the title says my turn signals quit working a bit ago. my hazards work fine though. i checked the turn signal fuse it is ok, swapped the flasher relay with the turn signal relay, flashers still worked but no turn signals. my truck does have a factory trailer harness on it so could the problem be in there?? or is it going to be something for the truck?

 

[franklin2]

Get a testlight. Pull the flasher for the turns and and probe the two terminals. One of them should have power. If not, double check that fuse again, and the wiring inbetween.

If you have power to the flasher, re-install it and then look at the bottom of the steering column if you do not want to take the steering wheel off. There should be a lightblue wire down there. This is the wire from the other side of the flasher that feeds the turnsignal switch. Poke that wire and see if you have power. If you don't, double check the socket in the fuse box where the flasher plugs in, it may be spread open and not making contact.

If you have power on the lightblue at the bottom of the steering column, the next step is to pull the steering wheel and probe the blue wire up there. By the way, do your brake lights work? They use the same wires and bulbs in the rear as the turnsignals use. The turnsignal switch takes the lightblue flasher wire, and the lightgreen brake pedal switch wire, and mixes them together depending on if you are turning, stopping, or stopping and turning.

 

[1990idi]

My brake lights work o both sides. I will have to check power this weekend

 

[1990idi]

Ok had 12 v at relay, 12v on light blue wire under steering column. So in order to heck at the switch the steering wheel has to come off? If I have 12 v on that wire does that indicate a bad switch?

 

[franklin2]

Yes, take the steering wheel off. If you have power on the lightblue going into the switch, then yes your switch has a problem, especially since your brake lights are working. The lightblue feeds the two sections of the switch. It has a section for the front turns, and a section for the rear brake/turns.

P.S. Just to make sure, take your hazard switch and move it in and out rapidly a few times and then try your regular turnsignals. Sometimes that hazard switch can get dirt in it, and it can interfere with the turnsignals.

 

[1990idi]

replaced the switch and the turn signals still didnt work....... just out of curioustiy could it be in the trailer harness??????

 

[Nick88745]

Yes. I have had this same problem , and I know your frustration... replacing the multifunction switch, checking fuses and so on. My company's primary mechanic fixed it and said it had something to do with the trailer harness, and he replaced the whole unit. I will ask him for you on Monday but it was two years ago and he might forget... as do I.

 

[franklin2]

replaced the switch and the turn signals still didnt work....... just out of curioustiy could it be in the trailer harness??????

Check that lightblue wire again. Are your signals coming on solid but not flashing?

 

[1990idi]

ok i apologize for not posting in a few weeks, anyways last night driving home from work for giggles i turned my turn signals on left the switch on for probably half a mile and all of a sudden the left side worked, turn it to the right side and it worked. left them on for about a mile hitting bumps and stuff. another mile later i go to turn them on and they dont work. i go to pull the relay out and it is very very very hot too the tough..... bad relay? or is there a broken wire?