What Pin On My 7-Way Should Be Hot All The Time?

Updated 04/26/2024 | Published 04/22/2024

Question:

Should the tm pin on my 7 way plug be hot all the time?

asked by: Otto L

Expert Reply:

Hello Otto. The 12v pin on your 7-way should be hot all the time, assuming it is wired directly to the vehicles battery. This would generally be the 1 o'clock pin. I have included the wiring diagram for a 7-way below for your reference. I am not quite sure what you mean by "tm pin" though so if you can provide more information, I am happy to provide you with a more detailed answer.

expert reply by: Jesse M

7 way diagram
(click to enlarge)

Otto B.

4/23/2024

My tail & running light pin is hot all the time, even with key off.

Jesse M.

4/23/2024

@OttoB The running light and tail light pins should not be active while the vehicle is off. The cause could be a defective converter box, or damaged wires/ a short.

Otto B.

4/25/2024

I took it to the dealer. They could not solve the problem. What would you recommend I do next? Do you know if there is another level of tech support at GMC?

Jesse M.

4/26/2024

@OttoB What is the year, make and model of this truck? Has it always been this way? Or is this an issue that arose recently? It is a bit odd that a GMC dealer could not address the issue, especially if this is a newer truck.