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Discussion Starter · #1 ·
My LT has a 6 post connector for a trailer already installed. My problem is the trailer that I have has 4 post connector. Can anyone help me out with a plan on wiring a four post connector using the existing 6 wires that are going to the previously installed connector.

Thanks

Matt
 

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Matt..
No way to "safely" know what's wired to where.... without having the bike to work on.

The easiest way is to rig up a FUSED "12Volt trouble light" that you can hook up to the NEGATIVE post of the battery and then you can "probe" each connector on the bike side..(yes, you'll probably have to lengthen the wires)

Just connect the FUSED lamp to the Negative battery terminal and with the other lamp wire touch each connector on the bike..while you have a bike function turned on. CAREFULLY so you do not touch more than the connector contacts.

Turn on the bike, then touch the connectors...
1- when the lamp lights, you have probably located "running lights"....
2- Write Down which connector it is.

Repeat the steps above for RIGHT TURN, LEFT TURN, BRAKE.

Don't forget, ONE of the connectors is probably "ground" or NEGATIVE side of the battery... so the light will NOT light on that one... As for the "other 2" connectors, there is no telling what they are for... I suggest you trace them out. They could be "constant power" to the trailer to run a trailer convenience light or brakes or.. who knows what the PO did.... That should do it.

Now, for the "trailer" part... if you can't trace the wires, you COULD rig up an external 12V battery, FUSED... then figure out which terminal on the TRAILER is GROUND... that goes to NEGATIVE post of battery.... then, carefully connect the FUSED wire to the POSITIVE terminal of the battery and CAREFULLY touch the other 3 connectors individually and document which LAMP on the trailer turns on.

Match the wiring on the trailer to the bike and go ride...
 

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You need to go and get a converter box at the local AUTO PARTS store.

European and Japanese cars & bikes use more lights than American autos use.

The converter box will make the two systems compatible.
 

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Here is another option. Add seperate turn signal lights to your trailer if it doesn't have them. The more lights the better. Then wire up the trailer to match the bike. You could run both units down here on saturday morning and we can talk about all the options and get it fixed up. I have everything you need including converters, 6 prong plugs, wire, and I have wired over 50 different bikes for trailers.
 

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Converter

you can most likely purchase a 'plug'n play' converter at any store that carries hitches/balls/wiring accys. I keep several of them in my truck tool box, never know what you might need ?
 

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You've already received a lot of good advice so here's my "take" on your issue.

A "standard" trailer uses a 4 wire harness and a ground,
left turn, right turn, tail light and brake light,
they use both turn signals as the brake lights.

the LT has a "seperate" brake light circuit,

you'll need to seperate this circuit from the turn signals
it is not going to work any other way
even with a converter (4 into 5)

I ended up installing seperate brake lights on my first trailer.

Another thing that hasn't been mentioned yet and is very important is an isolator relay,

it's possible that your bike already has one since you already have a 6 wire plug,

if not get one ($60 Bushtec or Dauntless)

the LT has some very sophisticated electronics (ABS, etc)
an electrical short could cost you more than the trailer.
 

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2005 K1200LT
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matt_rad73 said:
My LT has a 6 post connector for a trailer already installed. My problem is the trailer that I have has 4 post connector. Can anyone help me out with a plan on wiring a four post connector using the existing 6 wires that are going to the previously installed connector.

Thanks

Matt
I can save you a lot of grief as I just went through this on my bike.

I have the Bushtec isolator which has separate out puts for turn signals.

I went to Uhaul and bought their $16.95 coupler that take it to a 4 wire plug. The only thing that did not work correctly was the 4-way flashers. I tried other brands of couplers but they won't work with the Bushtec isolator because the need to "see" a bulb to ground . The Uhaul one also needs to see a bulb to ground but ONLY on the brake line.

I added an 82 ohm 5 watt resistor from the brake output of the Bushtec isolator to ground. Now the turn signals, brake and stop lights all work on the trailer AND I now have four way flasher working.

I highly recommend the Uhaul unit as it is cheap and water proof and has a nice connector on it. Best of all it works fine with the Bushtec and all you need to add is a resistor. (You could also just wire a small 12 bulb in place of the resistor.
 
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