Does anyone know which wire is for the reverse lights to hook up my auxillary lights so they will come on when i am in reverse.........04 F350 SRW

 

I taped mine from the actual reverse light. I would have to go check the color but I am thinking it was either blue with yellow tracer, or brown with white tracer.

 

USE EIther one that connects to the reverse lamp...
VERY easy to pull the lamp housing to check...

 

But I think there is two a hot and a ground. I would have to check again, been a while since I did mine.

 

I pulled the light and checked and it was a black wire with a purple stripe

 

If you have the tow package, pull from the trailer plug it is the center plug (7 pin). This will eliminate the extra draw and prevent blowing the fuse under the dash, the trailer plug is also fused as well. This is the way that I have hooked mine up, I also ran a wire from a switch in the cab to turn the lights on as well.

 

carbine 1, I hooked mine up to the trailer connecter, black with purple strip I believe. It works great. You can look in my gallery to see how I mounted them.

Fitter

 

I tapped the reverse lights on mine but I used a relay to prevent the extra load cangim is talking about. The lights get their power from the battery but only when the reverse lights activate the relay.

Scott

 

i wired mine up independently of the reverse lights for plowing. That way i can choose when to have them on. With my side lights, head lights, and reverse lights it looks like a space ship is landing when i plow.

 

When you connected them this way do they come on when your in reverse? Or do you have to switch them yourself?

 

I reaal would run an eternal relay just to be on the safe side.

 

They only come on when in reverse. I don't tow much and didn't put the relay in.

Fitter

 

In my old truck i burned up a bunch of wireing overloading the backup circuit with a set of tractor 5" headlights on the under the back bumper. it fried the neutral safety switch. Not shore if the superduty wireing is heaver than on my 94.

 

I thought the center post was a constant on for battery charging and interior lights in a camper/trailer?

 

On a 6-pin, the middle is the 12v hot. On the 7-pin, the 12v hot is the vehicle's #3 pin.

As far as being "constant on", it depends on the installation of your truck's 7-pin. My 2001 SD came with the "tow package" and had the 7-pin installed at the factory. Both the trailer brake line and the trailer charge line have relays which open when the key is off... This is to prevent these two lines from being "constant on" as you say and draining your truck's battery while parked.

However, an aftermarket installation could result in a constant 12v supply to these lines and risk a dead truck battery if left connected to your trailer overnight.

To the original question, I understand the Ford factory 7 pin uses the center (#7 pin or Aux) to provide reverse lights for trailers so wired. You could easily tap into this source and have reverse light power independent of your truck's reverse lights. As Cangim said above, this would reduce the chances of your aux reverse lights overloading your truck's reverse lighting system and all of them would still come on automatically when backing.

See the link below for a diagram of the 6 & 7-pin connectors.

Some Chevy Guy's 7 pin diagram

Edmo