I'm hooking up bed lights in the rear of the truck and wanted to pull power from the trailer connector plug. Putting a meter on red and black comes back with no voltage at all, with ignition on or off, doesn't matter.


I have an '04 with trailering package, fuse under the hood is intact (upper left of fusebox). Is this normal? I would have expected full time power to the plug. If there is supposed to be power, what other fuse could have been blown?

If you didn't take the fuse out of the brake pigtail that came with the truck, in the glove box usually, then what you see in the UHFP is a plastic fuse blank.


I think it has a sticker over it on the upper left side. Mine did.

I have the pigtail, it was wrapped with a wiring harness with electrical tape. I took it apart, there are 2 items. A 7 wire to 4 wire plug adapter. Then a wiring harness, with cut ends, but no fuse.


The upper left corner of the under hood fuse panel has a red square plug with B+ on it. There's a 10A fuse nearby designated for trailer.

I have the pigtail, it was wrapped with a wiring harness with electrical tape. I took it apart, there are 2 items. A 7 wire to 4 wire plug adapter. Then a wiring harness, with cut ends, but no fuse.


The upper left corner of the under hood fuse panel has a red square plug with B+ on it. There's a 10A fuse nearby designated for trailer.

The red square with a B+ on it is a blank. The <font size="3"><font color=GREEN>GREEN</font></font> 40A fuse is under the tape on the wiring harness. If you don't have one there, go to a parts store and get another.

Jim

ah, thank you. I'm assuming this is information I could or should have found in the owners manual. :) No fuse included, I'll buy one tomorrow, green 40 amp.


One last question. If the truck is equipped with an HD Trailering package, I'm wondering why Chevy would not install the fuse. Without the fuse, would the lights on a trailer still operate?

ah, thank you. I'm assuming this is information I could or should have found in the owners manual. :) No fuse included, I'll buy one tomorrow, green 40 amp. Dig around in that tape some more. It probabably is in there. It is mentioned on page 4-96 that the dealer can supply a harness for electric brakes and a fuse for the trailer battery. They also mention the dealer can supply the 7 to 4 adapter plug. My 1999 1500 gasser was the same way, but did not have the adapter.



One last question. If the truck is equipped with an HD Trailering package, I'm wondering why Chevy would not install the fuse. Without the fuse, would the lights on a trailer still operate? If you mean the tail, stop, turn and backup lights? yes, they have the fuses installed. It is just the 40A B+ that is not installed.

Jim

Edited by: jholly

on my 03 there is a two wire plug in drivers side rear bed stale pocket for power not sure what its for have never used it just noticed it.

The reason that the fuse is not installed is because you only need a 12v power supply back there if you are using electric brakes. To run electric brakes one must have an electric brake controler, with out the brake controller conected there is no 12v power supply to the rear anyways.


when you are pulling power from the trailer plug make sure it is the accessory wire(blue). This will supply 12v continously.

The following info works for a 2002 HD, not sure about others.


The 30A fuse which may have been supplied with the electric brake pig-tail is for electric brakes, which supplies power to your brake controller, for the Aux Supply Volt pin, (DK BLU), of the seven pin round connector. This fuse is inserted in the Fuse Block - UnderHood, at STUD 2.


My truck had no power to + pin, (RED), of the seven pin round trailer connector. I needed to install a fuse at STUD 1 in Fuse Block - Underhood. 12 VDC will ALWAYS be there now. Helms showed STUD 1 to be a 40A fuse, but I opted for a 30A fuse, because that's what my 5ver uses for protection.


Reference 2002 Helms page 8-309.

For my 04, there was no power to the red wire until I installed the 40A fuse in the Stud 1 slot. I tapped this to supply power via relay to the LED lights.

Havns3,


The extra wiring in the left front stake pocket is for Fifth wheel or


camper wiring. It was a factory option.


Jim

That fuse is for the Charge line power wire only. It has nothing to do with the electric brakes.