My wiring need...help...

Discussion in 'Wiring' started by SirLancelot, Jun 16, 2014.

  1. SirLancelot

    SirLancelot Member

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    First off, I'm not an electrical guru, but am far more of a "paint by numbers" kind of guy. I had to re-wire all of the trailer side of the 7- pin plug a few years ago. Everything worked with the exception of the reverse lights, which I wasn't concerned about. Check that - everything worked until I turned on the vehicle headlights and then tested everything again. Running lights and turn signals are fine , but when I press the brakes the reverse lights come on too.

    I'm trying to figure out in my head where I went wrong, but considering my non-guru status, am coming up dry. Short of testing continuity of each individual wire with a super long length of wire from the trailer plug to each light, do any of you have an idea? I virtually NEVER tow at night which is why I hadn't tested everything again with the running lights on.
     
  2. capy235co

    capy235co Member

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    I think we need more information. Are we talking PUP back up lights? If so are they separate from the Tail lights? A couple pictures here would help us out.
     
  3. SirLancelot

    SirLancelot Member

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    I'll try to clarify: each side has three sections. The outer one is the running lights, center is brakes/signals, inner is reverse. Brake and signals work fine with vehicle lights off. Reverse doesn't. If I'm not mistaken though, it looks like the reverse lights are super dim when the vehicle lights are off and the brakes are applied. Running lights work by themselves.

    Turn the vehicle lights on (trailer running lights on) and signals work as usual. Apply brakes and now the reverse lights go on and are super bright but the brake lamps are off. It's weird, I know. Reverse lights don't light up when I actually put the vehicle in reverse at all though, regardless of vehicle lights being on or off.

    I had to run the wire from the reverse bulb on our Suburban to the vehicle side of the 7 pin plug myself, so I recognize it's POSSIBLE it's t'd in to the wrong wire, but reverse is the bottom bulb in the assembly and that's what I connected to.

    I'm befuddled.
     
  4. Phranc

    Phranc New Member

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    On a 7 pin plug, the reverse pin should be the center tap. Also, make sure that the plug on the camper has a proper ground to the frame of the tongue. Also, make use the ground in the plug on the TV is connected to ground. Don't guess, use an ohm meter/multimeter to check.
     
  5. gruss

    gruss Active Member

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    since the lights that are working seem to change function when the TV lights are turned on...might want to make sure you have the correct relays in the TV. Did you have to add any to get it all working?

    when testing test each vehicle individually so you can isolate the issue. trailer is easy a couple alligator clips and a 12v source, maybe someone telling you which lights are on as you touch pins. But verify one works properly then move to the other.

    It does sound like a relay issue though, maybe compounded by a reversed wire somewhere?
     
  6. gerryrobinson

    gerryrobinson New Member

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    Here is a couple of diagrams to show proper wiring for the 7-poles. I would start there to make you don't have any wires crossed. If they are not correct and you need further help, pictures would help us help you.

    [​IMG]

    [​IMG]

    Pictures compliments of Etrailer.com
     
  7. SirLancelot

    SirLancelot Member

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    I didn't add any relays. Simply tapped into the appropriate wire and ran it to the plug. I had to disassemble and redo the wiring on the trailer side at the tongue too as the previous owner did (and admitted to) a total hack job at it himself and only had a 4-pin plug there with random extra wires bundled together and tied off with no labeling of any sort.

    I don't know how to check ohms with my voltmeter (it does, but I don't know what I'm looking at), but I do know how to check continuity. I may just try that. I accept the challenge. :)
     
  8. gruss

    gruss Active Member

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    Not familiar with dodges, but was wondering if the wires you tapped were from a factory harness in the back that actually provides fused lines for trailer lights (separate circuit from TV lights, so when you plug into a trailer that has issues you don't lose TV lights too) I know a lot of older fords had the wiring behind the tailight for 4 flat even if it didn't have any sort of tow package, so if you tapped something like that on your truck and not directly into the tail light feeds, get the owners manual out, and make sure all the relays in the fuse block (under the hood probably) are the proper part #/not burned up etc.

    It could just be crossed wires, that's why i suggested the testing the trailer lights first with a small battery and clips, take about 5 minutes to verify...but you say the lights work differently when lights are on/off on the TV leads me to think it's something factory that isn't working quite right.

    don't really need to test ohms, I'd leave it on 12 v clip the black on the ground of the bargman (or anywhere on the TV not painted) and verify each pin one at a time using the pics gerry provided.
     
  9. SirLancelot

    SirLancelot Member

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    In re-reading my earlier posts, I may need to clarify that my tow vehicle (Suburban) works perfectly. No problems there. There's a connector near the factory trailer hitch to insert a 4-pin connector to, which is what I did. There are two additional wires bundled nearby for 12v and brake controller. I had to run a separate wire from the reverse light bulb wire down to the new bundle of wires above (12v, brake, ground, tail, and signals). The car side of things works fine. It's the trailer side that has issues.

    When I purchased the trailer it came with a 4-flat wiring harness hacked up and spliced haphazardly into the original '89 Coleman square harness. I had to re-do all of that and run new 12v wiring and such to the battery. The original owner had a bundle of wires stuffed into the front a-frame of the trailer that I had to try to figure out. Some were obvious and easy, and others...were apparently less so...

    I'll try to trouble-shoot it all this week to figure it out. I'm not overly worked up about it as I never do tow at night (not afraid to at all, but if check-in is at 3pm, we leave mid-morning and if check-out is 11am, we get home by 3pm), but as I'm also a bit OCD about this stuff at times, I want to figure out where I went wrong... I'll update when I figure it out.
     
  10. gruss

    gruss Active Member

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    Yeah on our old pop up the running lights didn't work right either...I didn't worry about it for the same reasons BUT then I towed it home through heavy rain in the middle of the afternoon with the running lights all goobered up...a dim tail light etc and then the anxiety of gettin popped for faulty equipment or someone t boning the trailer set in so that next weekend I cut out all the "mods" from previous owners and got them working properly.

    Good luck, just take your time and test one function at a time, trailer lights are pretty simple you'll figure it out, and it will probably be a "duh" moment ;)
     
  11. SirLancelot

    SirLancelot Member

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    Ok, tow vehicle works perfect. Trailer is wired correctly all the way around. I figured out that continuity is perfect for the reverse lights, but when I reinsert the bulbs suddenly I start getting current through the tail/running lights. Not the signals, but just the tail/running lights. Do you figure I have a short in the wire for the backup or tail lights? I can't think of anything else. Pulling the offending wire through the frame shouldn't be TOO much trouble me thinks, but I don't want to do that without knowing what you smart folks think...
     
  12. gruss

    gruss Active Member

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    I think I'd test connections in your tailights before pulling new wires. Reverse lights on a PU are rare I think, very possible they're replacement and hacked in.

    Pull off a taillight and make sure whoever put them on did it right? Maybe they just wanted all the lights to work so tied in to available power...if my guess is right (just tied the hots together) you might need to pull a cable for reverse lights (or disconnect it all together, as you said how much will they get used)
     
  13. SirLancelot

    SirLancelot Member

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    I opened up the back and all wires and connections look completely original. The wiring schematic in the owner's manual shows reverse lights too. I'll have to test again with the vehicle hooked up (I tested continuity only today as the trailer is up) and see if just removing the reverse light bulbs takes care of it for now. I hate electrical stuff!
     
  14. sgip2000

    sgip2000 Member

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    Many older Apache trailers had reverse lights.

    Sent from my SM-N900T using Tapatalk
     
  15. gruss

    gruss Active Member

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    Hmm well there goes that theory.
    I guess now you just gotta find what might be crossed? start checking for continuity against the + poles of the different light sockets. Like tail lights and reverse lights should not show any. if you get a reading less than infinity thats where your problem could be. (disconnect all power ;) )
     

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