Turn Signal Problems

Hey y’all. I’ve read through all the prior turn signal problem threads on here, and none have dealt with the issue I’m having. My truck is a 2016 Limited. The symptoms are similar to a couple threads: Left turn signal randomly doesn’t work regardless of if you use the hazard switch or turn signal stalk. Sometimes it flashes once, then stops for my drive. Other times it stops for 5 minutes, then works the rest of the drive. Headlights, fog lights and driving lights have no affect on the issue and the right signal works perfectly. LED and halogens both have the issue. Resistors are installed, but are not the issue as you'll see with the troubleshooting I've done so far.

Troubleshooting thus far:

When the lights are all working: I took out the bulbs and got good readings from both driver and passenger side sockets on front and rear.

When the Driver side signals are not working: I took out driver and passenger side bulbs and received good voltage readings on the passenger side, but no readings on the driver side. I originally swapped the bulbs from driver to passenger, but this seems to be a wiring issue, not a bulb issue. I've had LED(s) and resistors installed for about a year with no issue, now I'm running into this mess. Disconnecting the resistor and putting halogens in does not remedy the issue when it occurs.

Due to everything working 90% of the time, I've somewhat narrowed the issue to be somewhere in the cab. Perhaps the hazard relay or the flasher relay are starting to go out? It's difficult to get a long troubleshooting session in due to the randomness of when it goes out. I am way past warranty on my truck (55k miles) and due to my remote start and other additions I know the dealer will just write it off and take my money.

Any ideas y'all have would be much appreciated!

-A confused and frustrated Zack

 

No idea where to start on this. Check fuse is not loose. Try to follow the ground from the light socket......

Boat trailers always had issues and standard phrase was ………. IT'S THE GROUND.... Maybe..?

 

That’s likely going to be the hazard switch/clicker. Seen this before. Got a Taco buddy?

 

Yeah ground checks good when it is working and not working...

Good old turd gen taco! Guess I'll be pulling dash pieces and driving around until it stops working again! It's my understanding that we have a relay for the turn signals. Does the wiring for the turn signal stalk go to the hazard switch or the other way around? My best guess is one of those three things are the issue?

 

I’m an old 1st genner forced to now own a 3rd gen but the electronics for hazards can’t be much different. The hazard switch is the “master” and the stalk is the slave if you get me. That shit has to work after you broke the stalk off pulling that hairy-balzack turn to impress the ladies.

 

LMAO ok that helps narrow it down to the hazard switch and/or the indicator relay.

 

What process are you using for verifying grounds and measuring for potential?

 

I'm unplugging the bulbs from the sockets, grounding one lead inside a bolt hole (for a non painted surface) and the other lead to the gound in the socket. Grounds all check good regardless of the lights working or malfunctioning. The only variation I've been able to narrow down at this point is the lack of power to my left signal's socket during the random non-working occurrences.

On a side note, new flasher relays are $45 and turn signal stalks are $95. I'm definitely troubleshooting more before I potentially throw $150 away for nothing.

 

I'm not familiar with the circuit but from my understanding there is only one turn signal stalk and one relay for both sides, if the relay or stalk were failing you would assume it drops the other bulb as well? If there are 2 relays then swap the working with the non-working and see if the issue swaps sides. Another thing to check for is to verify that your socket isn't broken in some way or causing a poor connection. One final note is that an improper ground can ring out fine but then when load is applied voltage will drop to 0.

 

I didn't realize we had a separate relay for each side. As for the possibility of an improper ground, I guess I'll need to get it to stop working again, and work from the hazard switch to the relay, and so on until I can find the voltage drop.

 

No I'm not sure if you do, I'm not familiar with the wiring for this it's possible that there is only one relay but if only one side is failing and its a single contact relay controlling both sides then both would drop out is what I'm saying, you need more information on the circuit to better troubleshoot this. If you have a wiring diagram I could possibly help more but it's all shots in the dark beyond this, finding where the voltage drops out is probably your best bet.

 

I've been scouring high and low for a wiring diagram. There are plenty detailing the wires at the sockets, but so far they're really lacking in availability for the cab's circuit. Thanks for the help man, I'll pm you if I'm able to find any schematics.

 

Flasher relay is built into the gauge cluster. Cannot he changed, or altered.

 

Well crap. Any ideas on how to proceed with troubleshooting the flasher?

 

This is insane. The Hazard switch is integrated into the air conditioning unit... ~$1,000 for a new one. And the flasher relay is integrated into the gauge cluster.... bloody hell.

 

Ok. That's fucked up.
I'm tapping out on this one man. Good luck and report back.

 

You could remove the wires to the cluster and add a 2015 flasher...

 

This is turning into a cluster.... pun intended...

 

Or dish out the 1K...

 

The "L" are to be T-tapped. The other removed (or cut n insulated) and connected to the 2nd Gen Flash Relay.