Troubleshooting Constant Power on Drivers Side Tail Light of Trailer Connector

Question

Question:

I have constant power to the left side tail light trailer wire harness. The harness in the truck when adapter is removed still shows power from Main harness. I disconnected 12 volt power at fuse panel and still have constant power to left tail light. Also when I turn the right blinker on in a trailer lights both tail lights blink. Left blinker blinks as normal. All brand new plugs Factory plug-in wiring all Newgrounds.

asked by: Brian P

0

Expert Reply:

It sounds like you have a crossed wire after the fuse panel. Sometimes this happens inside the trailer connector, so I recommend removing your trailer connector and using a circuit tester like # PTW2993 to test each of the wire functions at the US Car Connection locations like you see on this harness # 20147. If this connection works correctly then you will want to replace the 7-way connector on your vehicle because it has an internal issue. If this is the case, I recommend the Hopkins Endurance Multi-Tow 7-Way RV and 4-Way Flat # HM40950 or # HM40975.

If the harness is having the same issue on the US Car Connection then you will need to trace your wiring probing every few feet to determine the location of the short. If you can't find it, I recommend taking it to a mechanic to assist as the wiring does get complicated, but you should be able to trace it.

expert reply by: Jason S

0

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Answer 1

The problem has to be somewhere in the wiring. Was the 7-way recently replaced? It sounds like the 12 volt accessory circuit is either ran to the wrong terminal or is shorting out somehow to the 9:00 position of your trailer connector. Is there power…

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Answer 2

If I understand you correct you have a trailer with separate turn signals and brake lights that aren't functioning properly because you 2013 Ford F-150's trailer wiring combines those signals on one circuit. If I'm wrong let me know. If…

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Answer 3

There could be a few different issues with your setup but since you have towed the trailer with your other tow vehicle and there were no issues then that means the issue is with your 2012 GMC Terrain. I did not catch what trailer wiring harness that…

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Answer 4

In order to hook up a Blackstone Tailgater to the quick disconnect port on the side of a trailer you should be able to use the MB Sturgis RV Quick-Connect Propane Grill Hose part #100304-60-MBS or part #100304-120-MBS. I called Blackstone and they…

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Answer 5

It could be a tow package fuse on the vehicle. Use the owners manual to find the locations of fuses/relays related to the tow package wiring to check them and replace as needed. If the issue is not a fuse or relay then you can test the vehicle side…

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Answer 6

I tend to think it's a ground issue or potential short on your vehicle side wiring. Make sure that the vehicle side and trailer side connectors are clean and free of corrosion inside and out. The main connector ground should be attached to clean…

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Answer 7

The difference between the Class II and Class III hitches has to do with their Gross Trailer Weight (GTW), their Tongue Weight (TW), and their Hitch Receiver Size. Class II trailer hitch receivers have a 1-1/4 inch receiver and can be rated up to…

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Answer 8

A 4-Way trailer connector has the basic lighting functions only; running lights, left turn signal and brake lights, right turn signal and brake lights, and ground. A 7-Way has these functions and a 12 volt circuit, a circuit for electric trailer…

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Answer 9

In order to determine the torque rating for the lug nuts on your trailer you will need to know check out the chart I attached that shows all of the torque specs for all the trailer lugs available based on stud size, wheel material and wheel size.

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Answer 10

Lance does have a proprietary plug, but many customers see a standard 6-way or 7-way round and notice it doesn't fit their factory 7-way as well. I've attached an article to help if you have one of the 7-way or 6-way round connectors which we…

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Answer 11

You will have to go with a sliding hitch to allow the trailer to make tight turns. For a trailer 8 feet wide the only bed length that's going to allow 90 degree turns without a slider is a stationary hitch. That being said you have two options.…

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Answer 12

If you just need a 4-pin to 7-pin trailer wiring adapter, then you can use part #C57672. This will plug into the 4-pin trailer connector on your brother's vehicle and give him the 7-pin socket for the trailer. Keep in mind, this will only give…

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