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Under bumper back up lights how to wire

Discussion in 'Commercial Snow Removal' started by NEUSWEDE, Feb 12, 2005.


    NEUSWEDE Senior Member
    Messages: 949

    I am going to mount lights under my bumper like I have seen a lot of people do so when in reverse I have more light. How do I go about wiring up these lights so when the reverse lights kick on so do these?
    Also any good source for these? Napa?
  2. timm9

    timm9 Senior Member
    Messages: 168

    I'm no expert but this is what I did.

    I removed the tail light assembly. I then used a meter, with the trans in reverse to determine what wire was powering the back up lights. I then connected/jumpered off that wire and ran in down through the bed sidewall to the light I was installing.
  3. cbelawn

    cbelawn Member
    Messages: 39

    I tapped into the wire at the backup light socket and ran the wire along the bumper. My lights are mounted so they slide into my trailer hitch reciever and can be removed easyly. Purchase the lights at napa, a farm store, ect. I know a lighting rep so i get all mine as "demo". peace
  4. plowed

    plowed Senior Member
    Messages: 344

    To do it right, you need to run it through a relay. If you just tap into the circuit it will put a lot of amps through it and will lead to an overload. A guy I know did this and it ended up toasting the wiring harness and the whole truck almost caught fire. Do it right, do it once.
  5. oldmankent

    oldmankent PlowSite.com Addict
    Messages: 1,322

    I would not tap into the reverse lights of your truck. That could overload the wiring for those lights and lead to trouble. A great option if you have the trailer tow package from Ford is to splice off of the center pin of the seven pin hookup. You need to install the relays under the hood, and then just splice into the wire off the back of the connector. Just did this on my father's truck. It shares a 25 amp fuse with trailer running lights, so there is enough juice. Most trailers do not have back up lights anyhow, so likeliness of overloading this circuit is fairly slim. If you don't have the tow package, I would use the truck reverse lights to power a relay only, and then feed the lights directly from the battery and run a wire to the back of the truck to do so.

    NEUSWEDE Senior Member
    Messages: 949

    Yea I have the tow package. So I take the center wire from the 7 pin connection? I thought that was for trailer brake when a brake module was hooked up? If not I just take the power from both lights and tie it into the center wire? What relay under the hood? Sorry I am good around vechicles just wiring I am uneasy about because so much can go wrong.
  7. snow7899

    snow7899 Senior Member
    Messages: 234

    I use the same method, but I use all the trailer wiring for the relay inputs(ground, constant +12V, switched +12 reverse wire) and use a heavy duty weather proof 30A relay. The ford super duty's are the easiest to do because the trailer 7 wire harness can be removed from the truck and the work can be done on the bench. On some fords that have trailer connector check to make sure the fuse and the relay were installed at the factory, I've run into this a couple of times.

    NEUSWEDE Senior Member
    Messages: 949

    can I get possible a wiring diagram and which wires off the trailer wiring? Where do I get the relay and that goes inline with the wires up back or up front? Sorry I am a bit confused just need to break it down a bit more.
    Thanks sorry for being slow
  9. oldmankent

    oldmankent PlowSite.com Addict
    Messages: 1,322

    Neuswede, drop me a private message or email and I will either give you my phone number or write you a detailed email. Nick.
  10. Blizzard Plower

    Blizzard Plower Junior Member
    from Il
    Messages: 27


    SIPLOWGUY Senior Member
    Messages: 686

    You might want to consider a switch so when you don't need them you can shut them off.
  12. plowman350

    plowman350 Senior Member
    Messages: 125

    in line fuse to battery

    Okay, I did the same thing on my truck this fall, but didn't like the idea of tying them into my reverse lights. If you tie them to your reverse, you have a couple possible problems:
    1. Overloading of circuit
    2. Lights turn on and off Thousands of time.....leading to bulb burnout
    3. If you ever salt with the truck, you'll have to go in reverse to get any rear lights on!

    So, I ran a line directly from the battery (with an inline fuse). The trick to doing this right is using a double insulated wire which can be bought in bulk at the hardware store. I have this going through the firewall and to a toggle switch mounted up and to the right of the pedals. I just reach down and flip it on when I'm using it, and shut it off when I'm done, or the sun comes up.

    What's nice about this way is that you don't have to tap into existing circuits, your lights stay on and turn off at your choice. If you ever use a salt spreader and want to see the salt in your mirrors, you can leave the lights on. You won't burn through bulbs. Light bulbs burn out becuase of frequent temp changes, not from being left on. Putting them on your reverse lights will make them come on and off all the time.

    Items to buy:
    Back up lights - Farm Store, Plow Dealer, Auto Parts store $10 a piece
    Toggle Switch for in Cab - Auto Parts store - $6
    Double insulated wire - Auto Parts/Hardware/Home Depot $15
    In line fuse - Auto Parts store - $2

    IT takes longer to hook them up this way, and you need to know a little about auto electric systems, but in the long run, you have lights that you can turn on and off when you want, and with a lot less problems. I just leave them off all summer long.

    You can also hook them into your 4 pin/7pin trailer harness by hooking them up to your accessory line. This works too, but you have to get out of the truck to turn them on/off.
  13. Turfmower

    Turfmower Senior Member
    Messages: 376

    Wouldn't lights under the bumper be prone to breakage do to hitting snow banks?
  14. Blizzard Plower

    Blizzard Plower Junior Member
    from Il
    Messages: 27

    If you follow the link to the diagram Alan drew up, you can hook a wire and switch them on at any time.

    I did the same thing on my truck, but I have a switch to turn them off when not needed.

    So I have a switch to turn them on so when I put in reverse, the lights come on, and I have a switch to turn them onn so they stay on till I turn them off.

    BTW I also have a light that comes on when I hit the clutch for the salt spreader. Also used a relay.
  15. Blizzard Plower

    Blizzard Plower Junior Member
    from Il
    Messages: 27

    That plug is not ment to supply that kind of amps.

    The trailer pug is for 20 amp max...All together, all 7 leads.

    1-55 watt lamp pulls 15 amps.

    A 4 pin trailer plug does not have back up lamps.
  16. Blizzard Plower

    Blizzard Plower Junior Member
    from Il
    Messages: 27

    Ultility light or flood lights. Don't buy fog or driving lights.

    Toggle switch, or roacker switch (SPST)

    14 gauge wire, either doule insulated or wire loom will work. A 14 gauge or bigger extension cord willdo the trick.

    In line fuse ATO or ATC style with fuse cover.

    A relay.......do not forget a relay. No sence brinning that kind of amps inside the cab if you don't need to.

    Andvance Auto has all these parts.