Trailtech DC conversion went wrong!


Last days I have been trying to put to gether a used trailtech 100W DC conversion kit for my -04 WR 450. I didn´t come with the best of instructions so I have tried to use what I could find online.

Everything went fine until I was supposed to connect power to CD and Lights. This is were it might went wrong. From the reg/rec all leads were matched up according to the instructions.

The old stator harnes had 2 connectors, 1 red+black, 1 white+yellow. The red+black had the same connector on the trailtech stator harness, all good!

However the yellow+white from old stator when over to blue+white and had to be disconnected to remove old stator. According to trailtech instructions a wire should be tapped in on the red/black from behind the front light, down to the yellow+white that powers CDI and lights. My guess what that this on my bike was the white + blue that I disconnected from the old stator.

I know this is a bit tricky to follow, but this is what happended.

When I turned on the ignition switch, the led went on and also the tail light (like it should with a DC conversion I guess), but when I connected the front ligth (that had been disconnect for better access) the led went out and also tail ligt.

I leave the front light disconnect, led is lit + trail light, and I can start motor with the electric starter. Connect the head light, no LED, starter will run but engine woun´t start. To try to solve this I now cut the blue wire that I thought was for lights. After this step I can not light up the led nor start the engine with electric starter, and no tail light. The starter is running like it should and also the horn is working when ignitions sitch is on, but LED is not lit.

One could think that it would only be to connect the cut of blue wire again, but it does not work.

Have checked both 10A fuses and they look ok, and tested with the "Beep" function of my multimeter.

Im afraid I have damaged my CDI unit now so please help me out if you have any idea!

BR /Fredrik

Ok, guess I need some pics to clarify this.

Wires on the reg/rec side.


I´m pretty sure that this side is correct. I did not realize that the trail tech connector was supposed to use the red wire clip removed from the stock connector, so I changed the connector on both sides.

Except from this its according to the trail tech instructions.

And here is were I belive it went wrong:


The two red wires, that goes into one and connects to the Red/Black on the ignition switch, was supposed to connect to a white+yellow connector according to Trail tech instructions. I could not find this and guessed that this was the one to choose, blue+white.

When battery cable was attached, the ignition led worked. I Attached the gas tank and it started up nicely. Tried this serveral times. This was with head light detached. When attaching head light to see if it was lit up all the time, the ignition led went off, and on again when head lamp was again disconnected. Tail light was lit all the time when led was on.

I thought this was a lightning problem, so I cut the blue wire, that was suppoesed to be power for lights (see picture). Try to start again, but the there was no Led and no tail light.

Start motor and horn works when ignition switch is ON, but no light. When I measure into the head light socket with the "beep function" on the multi meter, It beeps all the time. This indicates a short, right?

Any clue what this could be? Thankful for all ideas! BR /Fredrik

Some more pictures, hopefully adding some value:

Crosscheck between Trailtech wiring and mine:


Some readings from behind the head lamp:


OK, now I have connected everything as it was with the stock regulator and stator, and now engine starts! The ignition LED is still not lit, wich is strange. I have now checked it with 12 V from the battery and it works. I guess this means that CDI is not damage wich was my biggest fear.

A bit worried about the charging voltage. When I measure with motor off I get 13 V over the battery. When measuring with motor on at 5000 rpm, only 13.5 V, same over rectifier (red + black wire). Is this to low? Its way out of spec according to the service manual with stock stator and regulator.

Now I expect someone to write something in this thread, other than me! :busted:

Ok, another update from myself. I think problem is solved, reconnected according to TT instructions but spliced CDI+light power on to the brown lead instead of the Black/red.

Conclusion is that something went wrong with my ignition switch at the first attempt.

According to other forums, + lead to head light had to be cut and rewired from battery get the charge working. Now I need to add some switched and that should hopefully be it! /Fredrik

I've been watching this thread and cant help to wonder if you bike is wired differently then the USA version which Trail Tech basis their stator off :busted:

Dont know. This bike was bought as " road legal" which means indicator lights etc. This could be why the white/yellow cables went over to blue/white. But it does not explain what happened witht he red+black cable on the first try. I will re route the headlight + wire the weekend, and hope fully charging will work after this.

Thanks for the updates. This will be a great resource for the next guy :busted:

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