Left blinker not working

This started after messing with the trailer wiring?

Do you have the tow package (7 way) plug?

 

The running lights went out after messing with the trailer plug trying to pin point the blinker issue

Yes I do

 

Interesting, I'd look the harnesses over very closely that you messed with. It seems your short would be near the area you messed with unless it's just coincidence.

 

For Towing it is combined signal & stop. This is done at the Combination meter PCB.

 

I've read through the thread and think I understand what you have done so far: Exchanged Combination Meters, grounded the turn signal stalk wire for the left-hand side all to no avail.

You might unplug the trailer 4/7 Pin connector (T12) at the bumper and look for corrosion and bent pins. Leave T12 disconnected and test the signals. Also reseat all the connectors within the engine bay fuse box; many of the trailer connections go through those connectors. Specifically, EB1, EB3 and EB4, it would take too long to explain which is which. Just do them all and take a good look at all the wires and contacts, again looking for corrosion and bent pins. Do not leave these engine bay fuse box connectors unplugged.

Do you have a towing brake controller installed at T7? If so, disconnect it, perhaps it has failed. Inspect it for corrosion.

Do you have the turn signal indicators on the mirrors? Curious only.

What puzzles me is that the combo meter has two different outputs for each side of the vehicle. One output to the left front indicators and one output to the left rear & mirror indicators; both are somehow affected.

My supposition is that the combo meter is seeing some resistance error on the wires that it is not programmed to detect and is babbling incoherently. The engineers can only program the combo meter to detect conditions they can think of; reality has different plans than the engineers. Could de-pin the combo meter connections and try each of the two left side connections separately. De-pinning can be difficult as many of the pins on this vehicle are very small (0.64mm).

Good luck.

 

Yes I do have turn indicators in the mirrors