8 Pin Trailer Plug

jonny72888 · June 27, 2011

I have a 7 pin plug on the back of my truck and the power wire has no power to it. I checked every fuse and did not find one that was bad. On my last truck that wire was "on" all the time. I can not get 12v at this one. I tried it with the truck running to and still nothing.

Bluedog · June 27, 2011

Replace the fake plastic fuse in the underhood fuse box marked stud #1 with a real one. Should work then.

jonny72888 · June 27, 2011

Replace the fake plastic fuse in the underhood fuse box marked stud #1 with a real one. Should work then.

I just got back from looking at it better and you are right. I was reading and saw that some trucks came with the wire disconnected so I went to look for that and found the fake fuse. In the manual it says "GAS TRUCKS DO NOT INSTALL STUD #1 FUSE". I put a fuse in there and I have power out back. why would the manual tell you not to install it?

Thanks for the help.

SparkySparks · June 27, 2011

Replace the fake plastic fuse in the underhood fuse box marked stud #1 with a real one. Should work then.

I just got back from looking at it better and you are right. I was reading and saw that some trucks came with the wire disconnected so I went to look for that and found the fake fuse. In the manual it says "GAS TRUCKS DO NOT INSTALL STUD #1 FUSE". I put a fuse in there and I have power out back. why would the manual tell you not to install it?

Thanks for the help.

Hmm, no clue, I don't think mine said not to install the fuse but I have a 2008.

Bluedog · June 28, 2011

Replace the fake plastic fuse in the underhood fuse box marked stud #1 with a real one. Should work then.

I just got back from looking at it better and you are right. I was reading and saw that some trucks came with the wire disconnected so I went to look for that and found the fake fuse. In the manual it says "GAS TRUCKS DO NOT INSTALL STUD #1 FUSE". I put a fuse in there and I have power out back. why would the manual tell you not to install it?

The manual is jacked up for that year. If you had the second battery option (TP-2) and you put a fuse in that location, the battery isolator didn't work and your trailer could run down both batteries and the truck wouldn't start. The printer left out the part of the paragraph that said that.

Hmm, no clue, I don't think mine said not to install the fuse but I have a 2008.

2008's came with the fuse installed, but the proper wire (taped up under the master cylinder) was not connected. To get power to the 7-pin, that wire had to be connected at the fuse box.