I have a 2004 Silverado with a 7 prong trailer harness kit.

The reverse lights are suppose to be hooked up to the centre pin so that when the truck goes into reverse, it turns of the brake solenoid on the boat trailer, which then turns the disc brakes on the trailer of, allowing me to reverse.

I have looked through the manual for fuses related to the traielr wiring, and checked a bunch under the hood and they all seem to be fine.

Are there any other fuses I should check and where would they be??

Thanks so much for any help, it is much appreciated!
Ian

 

is it a factory plug or was it added?

 

I beleive factory plugged.. Truck was bought used and the dealer made the impression to me that they installed it.

 

If it's seven pin, more than likely it's a popular factory trailering package which comes with a class I hitch on many models now.
Assuming that you've had no changes from stock wiring:
1)- page 5-125 of your owner's manual-(interior fuses, block located at driver's side dash left lower edge) on page 5-125 at the bottom of the page on the left "LT TRLR ST/TRN"-Left Turn Signal/Stop Trailer
2)On the same page, on the right "RT TRLR ST/TRN"-Right Turn Signal/Stop Trailer
3)Same page, above #1), "VEH CHMSL"-Vehicle and Trailer High Mounted Stop Lamp
4)Page 5-124, "SEO ACCY" -Special Equipment Option Accessory
5)Page 5-126- at "Center Instrument Panel Fuse Block" located underneath the instrument panel, to the left of the steering column,"SEO"-Special Equipment Option, and "TRAILER"-Trailer Brake Wiring
6)Under the hood,(Owner's Manual Page 5-128 thru 131) the fuse block is over the driver side wheel well.(Some creative rodent set up housekeeping in mine a few years ago, tearing insulation off the firewall to line his "nest", the little beggar.)"STUD 2"-Accessory Power/ Trailer Wiring Brake Feed.
7)Under the hood-"TRL PARK"-Parking Lamps Trailer Wiring
8)Under the hood "TRL B/U"-Backup Lamps Trailer Wiring

Before you start ripping your(by relative standards) very dependable truck apart, I would like to point out here that there's a good reason auto parts stores are so well stocked with replacement wiring for trailers. They are notorious for having faulty wiring. Exposure to weather 24/7/365 and the dunking boat trailers take when when they launch boats, combined with having minimal suspension, wreaks havoc on trailer wiring. Make sure the trailer's OK before blaming the truck.

B'dee,B'dee,B'dee- That's all folks!

 

Relating to the same topic but kinda of a trailer wiring question.

The wire for the reverse lamps which is hooked to the centre prong on the truck is there.
When I popped the trailer plug apart there is no wire going to the centre pin and there are two wires just hanging there. One red, one black.

I tried hooking up the red one last night and the trailer brakes still locked up. Should I try the black one?
I am assuming something on the trailer end would have to be hooked up to the centre pin on the trailer plug for it to receive power to turn of the solenoid on the trailer.. correct?

There is nothing hokoed up to the centre pin and one screw hook up has nothing attached to it either.

Thanks for all your help!