Trailer Lights

Discussion in 'Road Safety Systems' started by Clawhauser, Apr 8, 2021.

  1. jeepster04

    jeepster04 Active Member

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    A ground through the hitch should not even be considered. You should be able to hook up the 7 pin wiring and everything work fine with the trailer not hitched.
     
  2. tfischer

    tfischer A bad day camping beats a good day at the office Gold Supporting Member

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    You should be able to use a multimeter or 12V test light and verify that things work at the TV, without the trailer even in the picture.

    Far too little information here to be throwing out specific solutions, especially since this is a new installation done by an amateur with no experience that has never yet worked.
     
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  3. Snow

    Snow Well-Known Member

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    It should, but many times the ground wire on the vehicle isn't connected. Also if you have a brake controller (tekonsha ones anyways) actually use the hitch ground to sense when the trailer is connected.. both of my bc's ( Voyageur and P3) show when the trailer is physically on the hitch..
     
  4. Snow

    Snow Well-Known Member

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    Unless you have a Tekonsha bc.. they actually use the hitch ground to complete the circuit or at least my 2 do (Voyageur the light changes to green when trailer is hitched, P3 actually displays the trailer is hitched), unhutched or a trailer like my utility trailer which has a 7 way plug but no brakes, they both signal no trailer.. there is actually a blurb in their manuals that if you don't get the trailer attached indication to check for excessive corrosion..
     
  5. jeepster04

    jeepster04 Active Member

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    My brake controller also shows when a trailer is hooked up... That means it see's the resistance of the magnets in the trailer brakes... If the trailer didn't have a ground, which it will if the trailer is properly wired, then its possible to have the brake controller only show a trailer when the trailer is hitched... My ball mounts are wrapped in a thick rubber tape to keep them from rattling, so that wouldn't work anyway.... I could have my trailer 20' away from my tow vehicle and if I could hook up the 7 pin, it would show my trailer being connected.

    Anyway, it sounds like the OP has a poor installation on the tow vehicle so this is a moot point.
     
  6. Snow

    Snow Well-Known Member

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    With mine plugged in, it shows they are electrically connected, but without them hitched up, the trailer doesn't show.. likewise, when hitched up and not plugged in, they show the trailer but shows no power to it.. makes for a fool proof way to ensure both the trailer is hitched and the plug is in. The P3 shows all this with images, words and colors.. the Voyageur just uses one 4 color led green for good, yellow for either no plug, or not hitched, orange and red are for amount of braking power..

    You're right though it is a moot point in this case but the double ground is a safety thing, with your hitch wrapped in rubber, if you were to loose the 7way ground, you'd loose your brakes..
     
  7. tombiasi

    tombiasi Well-Known Member

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    Do you really need electronics to know if your trailer is on the ball? Hitch ground should never be relied upon as a ground.
     
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  8. Snow

    Snow Well-Known Member

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    Tell that too my brake controllers.. that is how they are designed to work..
     
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  9. tombiasi

    tombiasi Well-Known Member

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    What brake controllers do you have?
     
  10. Clawhauser

    Clawhauser Member

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    Tow vehicle.

    @Raycfe , yea that's what I'm afraid of.
     
  11. phipps

    phipps Member

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    So, you're saying if your trailer is on the ball, but not plugged in the controller shows the trailer is on the ball?!? Hog wash. Not sure what you've been smoking. Without the trailer being plugged in to complete a circuit it isn't going to happen. I had a P3 for many years and a Voyager before that and I assure they do not work that way.
     
  12. NEODon

    NEODon Tired but not retired Gold Supporting Member

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    EDIT: I had missed the post about the fried circuit board. My comments here the might help someone just troubleshooting new trailer light hook-up problems but not so much the situation in this thread. - On our 1st trip out with our new-to-us trailer I had just installed the hitch & the trailer light harness/interface on & in our 2005 Tucson. Long story that I probably won't remember all of but the lights did some really strange things. It ended up being that the interface would not work with regular light bulbs in the tail lights of the trailer, it needed LEDs in the taillights. It seemed like maybe the electronic interface that was part of the new harness did not have the guts to run regular bulbs. I did also chase the grounding issue around & around. I had everything installed correctly. It was a defective or at least deficient interface. I was not going to try to return it since I had run the wires in places that I did not want to go to again if I didn't have to. In the old days you just tapped into the wiring that went to the TV's tail lights, no interface was needed which made things fairly easy to troubleshoot. Now with the little black interface box, things can get complicated.
     
    Last edited: Apr 13, 2021
  13. RonDad

    RonDad Member

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    The insulation installation [:D]
     

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