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How Does the Roadmaster Tow Bar Wiring Kit # RM-154 Install on a GMC Jimmy


Hi there, I have flat-tow wiring harness part # RM-154. While I appreciate your diagrams and instructional videos, Im having trouble applying them to my 2005 GMC Jimmy. If youre American, that may not make any sense, since production of these stopped after 2002 in the US. It continued to the 2005 model year elsewhere. Presumably, my truck would be almost identical to an American version of the 2002 Jimmy/Blazer. My tail lights are three-wire, not two-wire as in your diagrams and videos. I have two bulbs, both with three wires. In your diagrams and videos, you refer to the yellow wire, which I do not have. They also refer to two wires, but do not mention the third one I have. I am certainly open to suggestions. So far, all I can get to work is the licence plate light. If you have the time and inclination, I could sure use a little help. Thank you for your time and attention. It is much appreciated. Cheers,


Expert Reply:

The three wires of the taillights of your 2005 GMC Jimmy are for, ground, low intensity (running light), and high intensity (blinker/stoplight).

The colors of the wires aren't what you need to pay attention to. You need to test the wires for voltage when the brake lights are on, and then when the taillights are on. Once you have established the functions of each wire you will need to wire up the # RM-154 like the diagram I attached to the right shows.

The yellow wire of the diagram represents the yellow wire of the # RM-154 and not the wiring of your Jimmy. This wire will get run to the towed vehicles left turn/brake light wire that you previously determined.

I also attached a set of installation instructions for this type of install for you to check out as well.

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expert reply by:
Jameson C

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