Trailer wiring 99 XII

[dcmrn1959]

How do I go about wiring a trailer on my 99 XII. Haven't seen any post on the subject directly. Saw someone had mentioned a "relay"? any help is appreciated. I found the wiring harness under the trunk but wanted to double check here before going any farther. Thanks Dan

[doug of so fla]

First you have to know that a MC is wired different than a auto, as the turn signals on a mc are on a separate circuit than brake & running lights. Auto, they are on same circuit. Which means you have to purchase a adapter, Walmart or Napa has them $20.00, "Hoppy" is a good brand name. You can wire it up same as MC by using separate turn lights and brake & running lights on the trailer. When you do it this way or even with the adapter you may want to think about using all led lights which will eliminate drawing to many amps thru the MC system. The preferred way is using the adapter, as all the trailer to vehicle connector plugs are made for autos. A relay should be used if you stay with conventional bulbs (12v). You do not need relay running LED lights as they do not draw as much power but you could if you wanted.
The easiest way is to put adapter in trunk and splice wires into correct mc wires in trunk. To connect wires to turn signals, Run adapter wires down thru grommet hole in trunk and connect to signal wires coming from each saddle bag. 3M makes a connector that folds over a wire and after it is folded it forms a female blade connector and then you connect the male end blade connector to the adapter wire. This is so you can unplug the wires if you need to. I have never had a problem with these connectors. Some like to solder everything which is a good way also. All the wires you need are accessible in the trunk except the signal wires. To get power use the xtra connector under the tour trunk. Use a test light to find correct wires in trunk. Any questions e-mail me I have done many MC to Trlr hook-ups for the XII..

[chevyman1]

If the trailer is 5 wire you don't need any adapter
A 5 wire trailer will have the turn signals separate from the tail/brake lights

[dcmrn1959]

Thanks for the info, very helpful. Off to get the adapter. Trailer is 4 wire. Thanks again for all.the help. Dan