Finding backup light wires...
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Joined: Aug 2005
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Finding backup light wires...
I have a 2001 F250. I want to add some aux lighting in the rear, the stock BU lights are junk. I found the tube of wires going up to the lights from under the bed, and I'm assuming there are 3 in there - Brake lights, turn signals and BU. Does anyone know from experience or a wiring diagram which one I need to tap? I'm planning on tapping the hot wire and grounding to the frame or body so they come on when in reverse. I know I could run wires to a switch on the dash but prefer not to. I feel sure some of you have done this after driving in reverse at night, or trying to load decoys and guns in the boat at O Dark thirty....!! Thanks.
More Turbo
Joined: Aug 2004
Posts: 577
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From: Georgia
I had bought a pair of tractor flood lights from Wal-Mart and installed them beside the hitch receiver using the holes already under the bumper. I had to move the trailer wiring connector and mount to the left a little. I spliced into the stock backup light wiring. It worked but the brightness wasn't there so I ran a 12 gauge wire from the battery to a relay and connected my lights to it along with the spliced wiring to the stock lights to be used as a trigger mechanism. Boy did that make a big difference in the brightness. Then I connected a SPDT (single pole double throw) on-off-on switch so I can turn on the new lights without putting the truck in reverse. I found a wiring diagram posted by one of our users named Deaver that showed a switch with four pins, one being for a ground. But I had trouble finding a switch that has four pins. All I found had only three pins.
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Lead Driver
Joined: May 2003
Posts: 9,303
Likes: 48
From: Lyndonville, Vermont
Yes you need a relay, Unless your truck has the tow package or maybe camper package it will have a backup relay or place for one and the wire will be all the way to the back already..
Dick
Dick
Lead Driver
Joined: May 2003
Posts: 9,303
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From: Lyndonville, Vermont
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Bump... I'm trying to clarify something for myself...
I'm trying to figure out of I can get +12V fused at the back of the truck at the trailer connector. I'm planning to take power from a wire in there, run that to the relay, then from the relay to my lights. The trigger wire coming into the relay to activate it will be the black/green wire at the trailer plug.
But which wire do I use for the power to the relay? There's an orange wire going into the trailer plug, and the little picture just shows "+" for what it is - is this the 12V power I can use to power the relay?
I'm trying to figure out of I can get +12V fused at the back of the truck at the trailer connector. I'm planning to take power from a wire in there, run that to the relay, then from the relay to my lights. The trigger wire coming into the relay to activate it will be the black/green wire at the trailer plug.
But which wire do I use for the power to the relay? There's an orange wire going into the trailer plug, and the little picture just shows "+" for what it is - is this the 12V power I can use to power the relay?
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Brett Foote
Lead Driver
Joined: May 2003
Posts: 9,303
Likes: 48
From: Lyndonville, Vermont
The orange wire is the trailer charge wire that should be hot if you have all the relay's up front when the key is on...Why can't you just use the backup wire that goes back there its for trailer backup lights, you shouldn't need a relay unless you are doing something you haven't told us. That backup wire runs off a relay under the hood anyways..
Dick
Dick
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Joined: Mar 2004
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Hey Dick,
I'm setting up two lights, each with duall 55W filaments, so a total of 220W (about 18.3 amps drawn, would that be correct?)
I did some more reading after posting this earlier, and realized that there is the extra fuse box under the hood, and that the relay in the front position is for the backup lights off the trailer plug.
** Does this mean that that relay is already powered, and is already set up to be triggered by shifting into reverse, and it's output wire is the black/green wire at the trailer plug? So, I can simply run off the black/green wire to my lights POWER wires, and then run my light's ground wires either to the white wire at the plug, or to the frame/body? And I guess if it's already fused for 20 amps, like you had posted earlier in the thread, that should be enough for the 18.3 amps my lights will draw.
I appreciate the help, Dick... looking forward to hearing back from you just to be sure.
Ryan
I'm setting up two lights, each with duall 55W filaments, so a total of 220W (about 18.3 amps drawn, would that be correct?)
I did some more reading after posting this earlier, and realized that there is the extra fuse box under the hood, and that the relay in the front position is for the backup lights off the trailer plug.
** Does this mean that that relay is already powered, and is already set up to be triggered by shifting into reverse, and it's output wire is the black/green wire at the trailer plug? So, I can simply run off the black/green wire to my lights POWER wires, and then run my light's ground wires either to the white wire at the plug, or to the frame/body? And I guess if it's already fused for 20 amps, like you had posted earlier in the thread, that should be enough for the 18.3 amps my lights will draw.
I appreciate the help, Dick... looking forward to hearing back from you just to be sure.
Ryan
Lead Driver
Joined: May 2003
Posts: 9,303
Likes: 48
From: Lyndonville, Vermont
Yes you are correct. The amperage will be about 15 -18 amps 15 when the truck is running and 18. something when off. Throw a 25 amp fuse in there and go for it. Pull the backup relay and see if it kills the voltage going back to the black/green wire to make sure all the circuts are working .....In reverse of course..
Dick
Dick
Lead Driver
Joined: May 2003
Posts: 9,303
Likes: 48
From: Lyndonville, Vermont
No just pull the 20 amp fuse out under the hood and replace with a 25 cause your trailer running lights come off the same fuse...You are cutting it close, thats alot of amps back there.
Dick
Dick