Auxilary power or B+ to 7 wire trailer plug

XTREEM

MEMBER
GMC SAVANA

I just purchased a new 2007 GMC Savana 2500 cargo 6.0L with the towing package. I have been unable to get 12 volts B+ at he 7 wire connector that was tucked up in the frame rail at the rear of the vehicle. The user manual indicates that maxi fuse #50 in the underhood fuse box is for "Trailer" It is present and has power. Is there someting else I need to connect to enable auxilary power for the trailer?

Wednesday, July 18th, 2007 AT 9:44 AM

5 Replies

2CARPRO JACK

MECHANIC
11,533 POSTS

Im not sure it is wired to have a dedicated 12 post. Check the under dash fuse panel for any trailer or accesory fuses that may be missing

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Wednesday, July 18th, 2007 AT 2:41 PM

XTREEM

MEMBER
2 POSTS

My owners manual states that the 7 wire plug on the back of the vehicle does support a 12volt B+ connection. I have found out that it is common on vans and trucks that the manufacturer will leave the wire or the fuse disconnected. The 7 wire connector is an industry standard and included on the factory wiring harness. I just need to know where to look to connect it on my particular vehicle.

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Wednesday, July 18th, 2007 AT 5:01 PM

2CARPRO JACK

MECHANIC
11,533 POSTS

My software doesnt have any diagrams for that new of a vehicle. Look in both fuse centers for missing fuses

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Thursday, July 19th, 2007 AT 7:38 AM

DC63122

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1 POST

There is some wiring under the dash on the vans that is not connected there on the new ones and I am also wondering where is the fusebox under the dash I found the one under the hood what a great idea to put it there haha.I have no power to the back of my trailer socket for the running lights would anyone know what the power comes for this.

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Saturday, December 15th, 2007 AT 10:57 PM

2CARPRO JACK