Turn signals (blinkers) not working why?

According to Sylvania the rear turn signal bulb should be a 4157. You could possibly have a faulty bulb socket due to loose terminals that will make a break contact with the bulb, thus the bulb that worked for a day. You can do some basic circuit tests at the socket to check for power and ground as this will verify if your issue is with the bulb or the circuit/s. I attached a basic test with a voltmeter to verify power and ground with the turn signal switch in the right turn position with the key on. If you don't show voltage place the ground lead on a good chassis ground, if it then reads voltage... bam! a bad ground, to which you can either wire in your own ground or hunt for the broken/corroded wire. This guide can help us fix it.

https://www.2carpros.com/articles/turn-signals-not-working-blinker

If there is still no voltage reading after trying a different voltmeter ground, remove the column shroud to access the switch and check voltage at the yellow wire, if no voltage there=bad switch, If voltage good, trace the circuit until you find the broken wire or run your own wire from the switch to the rear (no fun). Hope this helps!

Excellent! Let us know what you find!

It does sounds like the flasher unit but to be sure this guide can help us fix it I have added the flasher location int ehdaigrams below.

https://www.2carpros.com/articles/turn-signals-not-working-blinker

Check out the diagrams (Below). Please let us know what happens. They call it an indicator relay

Hi,

First, I attached the wiring schematic for the entire exterior lighting system for your review. I had to cut the pics in half to make them readable; however, I did overlap them so you can follow from one to the next.

If you look at pic 1, I highlighted the flasher and its location. pics 2, 3, and 4 are the remainder of the schematic.

If you look at pic 5, it shows the location of the auxiliary relay box #1. The last pic indicates the flasher's location.

Here is a link you may find helpful when testing:

https://www.2carpros.com/articles/how-to-check-wiring

I hope this helps. Let me know if you have other questions.

Take care,

See pics below.

Hello,

It sounds like the multi function switch is not working. To confirm lets use this guide to check for power at the switch with the blinker and brake light wiring diagrams below, also lets check for power at the fuses.

https://www.2carpros.com/articles/how-to-use-a-test-light-circuit-tester

Check out the diagrams (below). Please let us know what you find. We are interested to see what it is.

Can you please check fuse # 3 and #7 in the fuse box inside the truck?

https://www.2carpros.com/articles/how-to-check-a-car-fuse

Please run down this guide and report back.

There is a flasher relay that sounds like it is bad here is the location. Check out the diagrams (below). Please let us know what you find.

It is mounted below the air filter housing. I’ve added a picture along with the relay box layout. Hope this helps!

Glad you could get it fixed, that kind of problem can be tough. Please use 2CarPros anytime we are here to help.

Yes that's the one, my apologies for a bad picture!