I just purchased a 1990 Ford F150 Lariat. The turn signals and hazard lights did not work when I bought it. I figured that it was an easy fix and have no history on the vehicle.
I checked every fuse -- all were fine.
So, I figured that it could be a faulty turn signal flasher.
I replaced the turn signal flasher -- still nothing. Then suddenly I heard a random noise coming from the glovebox area. There, I located a separate hazard flasher. I replaced the flasher with the new one and had the same result with the original -- random flashing.
So, after a few hours of tracing wires and trying different flashers, the rear lights flash but not the front. Still no turn signals. For a few minutes one front light flashed with the two rears. If I turn the turn signal switch it stops the rear hazard on that side.
I have never seen anything like this before. Is this a problematic turn signal switch? If so, how do I replace it? Thank you in advance for your help.
The turn signal/hazard flasher/brake light wiring is very complicated. Not only does the switches and flashers have to separate left from right for blinkers but front from back for the brake lights and hazards. This is all done through the multi function switch and flashers. Checking all the sockets like wde3477 suggested is a good idea along with the connections at the flashers, but I do thing the problem is with the multi function switch.
Originally Posted by Early Cuyler
Fights begin, fingerprints are took, days is lost, bail is made, court dates are ignored, cycle is repeated.
Thanks for the input. The bulbs appear fine, and voltage is present. I think that I may replace the complete switch and see what happens. I assume that I should remove the steering wheel in order to replace the switch? Any tips?
Suggest to find a shop manual that has an exploded diagram of the steering column. It will likely have some instructions on the switch replacement too.
Yes, the steering wheel will have to come off. The special puller is recommended. Also, recommend to match-mark things so that the wheel will go back on in the same place, to keep the steering wheel lined up right when going down the road.
I'm new to the forum and also just bought a 1990 f150 with identical symptoms as listed above. A new turn signal switch from autozone fixed all of the problems and costs only $54. To install it, remove the steering wheel cover with the two philips head screws in the rear of the steering wheel. Next loosen the nut and use a puller to remove the steering wheel. Remove the two screws holding the old turn signal switch as well as the 1/4" screw holding a white plastic block connected to the switch with a dark wire. Cut the old harness plug off and pull the old switch out. Now the painful part. Take the new switch and cut the plug off of that allowing enough wire at the plug to strip, solder, and heat shrink. Run the wires back through the column. Now you can solder the plug back on and heat shrink it. I wrapped it with electrical tape from the plug up to the switch to give it the factory look and keep the wires together. The new switch is kind of a pain to get all the way back on the column as there are two pins that must go into existing holes. You know you have it correct when the new switch sets flush on the column. Reinstall the two philips head screws and the 1/4" screw into the plastic block. Place some dielectric grease on the back of the steering wheel where the two contacts ride and reinstall the steering wheel. There are two marks, one on the wheel and one on the shaft for realignment. The rest is pretty easy. I'm not sure if this is the correct way to do this but it worked for me and it save alot of time from having the tear the steering column completely apart. Hope this helps...