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Discussion Starter #1
Hi!
So I have a 1999 LT, battery was being destroyed rapidly and I found that by pulling the cable from the positive post of the battery that leads to the reversing control box, the battery drained more slowly. When I put a voltmeter on it, it shows connectivity to ground and obviously my reverse doesn't work. What am I missing here, that cable shouldn't go to ground, right? Anyway, I just hooked it back on cause I need to use the reverse, am I going to smoke anything by doing so?
Thanks,
Pat
 

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Wrencher Extraordinaire
2005 K1200LT
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There are three large(10 mm diam) black w/yellow stripe wires that go to the Reverser Controller (RC for short). The way you tell them apart is the color of the sleeve at the end of the cable. The black sleeve goes to the starter tie point behind the battery. The Brown one goes to the ground tie point behind the battery. The last one with a red sleeve goes to the battery (+). If that is what you have then it could be the RC has failed and is in the process of melting down. I say this because the solid state device that regulates the current is potted and when it fail it melts the potting. If that red sleeve wire draws a big spark and gets warm when you hold it on the battery (+) then you have a failed RC. Safest thing is just leave that lead off of the battery until you can find a used on on e-bay. The tie point photo is from an 05 so there is more "stuff" around the tie points but they are the same on your bike.

170712
170713
 

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Discussion Starter #3
Thanks J, that's exactly the advice I needed. I've taken the wire back off and will look for a controller.
How can you tell if an RC from someone on ebay etc. is good? I hope it's not pot luck :cool:
 

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2005 K1200LT
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They just don't fail that often so chances are good. I have only heard of two in the last 15 years. I am curious if you have the ability to measure current as I would like to know what the draw on the lead was. If it is good it should be very low, less than a few 100 milliamps, but if failed it could be on the order of 10's of amps.
 

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Discussion Starter #5
I do have a dvom, tell me what you want me to do and I'll measure it.
Lead to ground?
Interestingly enough, that lead will arc to ground with the key in the on position but I just discovered that it does not with the key in the lock position.
 

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Discussion Starter #6
Actually, now that I remember, I originally took it off because the frame of the bike was hot, so I knew it was a dead short. I thought that it was the abs unit, which failed a few weeks earlier though.
 

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2005 K1200LT
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Like I said the device in side is potted and that potting usually melts and flows out when they fail. Best to leave it off. You may damage your meter is you try to measure the current, but if you were to try you place one lead on the wire and the other on the battery + usually home dvoms have a small amperage scale and a separate place to plug the lead into for a 10 amp scale. Worst case you blow the little 10 amp fuse in side the meter but the rest of the functions will still work.
 

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Discussion Starter #8
Hmm, ok, my meter has an amp clamp so I would have to have all of the wires properly connected in order to measure that which goes through the red lead, between the RC and the + battery post, right?
There must be a hefty capacitor in that RC, for example; this morning I checked the unattached lead to ground for voltage and had none. I touched the lead to the positive post of the battery and had an arc, then read 12v with the same situation, unattached lead to ground. From there I rotated key positions and it seems as if the lead would have voltage in all positions for a while but declined over a minute or two. Finally there was no voltage with the key in the lock position but yet still in the others.
I will replace it for sure but can you tell me what it is supposed to look like from a voltage perspective so I'll know if the new one is acting correctly?
Thanks so much!
Pat
 

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2005 K1200LT
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That is the main power feed to the RC for operating the starter for reverse but there are other power inputs to the RC from the barrel connectors under the pillion seat. You may be seeing the other sources. Yes just put the clamp over the wire and then hold it to the battery post and get a current measurement. It should be very low on a good unit, high on a bad one.
 

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2005 K1200LT
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No I just want to see if it is drawing current statically, key off. That is the meltdown symptom high current draw and melting of the potting. If it is working OK then I don't think you have an issue.
 

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When I bought my bike, the dealer said that reverse didn't work. I bought it anyhow. When I got it home I looked into the wiring on this forum and realized the lead was hooked up to the negative post on the battery. I was worried the reverse would be messed up, but when I hooked it up to the positive, it worked fine. I then told the dealer about it.
 

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just cleaning batt posts when I put the neg back on i got a big spark and burnt insulation smell from left side looks like the rev, controller. I saw one on ebay yesterday had to leave later it was gone. are they all the same? I have a 2003.
 

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2005 K1200LT
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Yes they are the same for all years of the LT. But before you replace it it is normal for a big spark when the battery has been disconnected for some time. Try it again then momentarily pull it off then put it right back on if you get the big spark again you have an issue but if not then you may be OK.
 
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