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Another K1200LT reverse issue.

5K views 22 replies 5 participants last post by  jzeiler 
#1 ·
I’m finishing up a clutch job on a 2003 K1200LT and can’t get reverse to work.

Bike running on the center stand, F/R switch in R, transmission in neutral. The rear wheel won’t move when I check it (spins freely if F/R switch is in F) The Reverse indicator is on at the dash. Push the starter button, the rear wheel doesn’t spin.

I used my volt meter to check for power at the starter tie point. Negative meter lead on the battery negative, positive lead on the tie point, push starter button, no power.

One interesting fact, the bike WILL start with the side stand down which is not correct. I know I’ve missed something simple.

Please advise, Thanks.
 
#2 ·
Is there a switch on the centerstand that could lock out reverse when the centerstand is deployed? I don’t know.
 
#3 ·
Typically the side stand switch will prevent the bike from doing either function if the stand is down. In this cas the starter button starts the bike regardless of position. In reverse mode the starter button doesn’t do anything regardless of the position of the stand.


After scouring this forum I’m suspecting that either my speed sensor isn’t properly seated or one of the round plugs off of the reverse unit isn’t properly seated.

I’m still open to any input I can get.
 
#4 · (Edited)
If the starter works in F and not in R then you broke the tips off the FR switch or it is installed wrong when you put it back on the transmission. Center stand does nothing to prevent start.

But if the R light comes on then there is another issue.

The starter tie point is behind the battery and is where the reverse controller sends a reduced voltage to the starter for reversing. Maybe you left a wire off Black w/Yellow stripe and a black sleeve at the eyelet.

Also that signal from the switch goes through one of those two barrels for reverse.
 

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#6 · (Edited)
No fuse just for reverse. When you press the starter in "R" does the engine RPM change? I do not suspect the speed sensor as it's failure mode is a very short reverse distance, requiring you to release the button and press it again.

The side stand switch signal goes through the barrel connector with seven wires on the reverser controller so I would check that barrel and jack it a few times.
 
#9 ·
Thanks for the reply and your help. The RPMs do not change when the start button is pushed. Im about to check the 7 pin connector against all of the corresponding color coded ends in the harness. Hopefully I’ll find the problem today. I’m all about learning new stuff and even more about turning out a nice job but I need this bike off my lift. I won’t let it leave here not correct. I love a challenge but Airheads are so easy, I’m spoiled.


Thanks again for all of your help.
 
#10 ·
I’ve been through everything with my Fluke meter and all of the circuits associated with the reverse control unit check out.

I’m convinced it’s a bad reverse control unit. The bike starts with the side stand up or down, that switch meters correctly. The side stand switch goes through the RCU via pin 4 in the 7 pin barrel. It’s ground runs through the RCU via pin 1 in the 10 pin barrel. The starter will engage in first gear and spin the rear wheel, that is definitely not correct. The “neutral safety switch” shares a ground with the side stand switch. The Brown/Blue wire from the neutral safety switch runs through the RCU via pin 7 of the 7 pin barrel.

Am I missing something? It’s seems reasonable to assume that the RCU is bad.

Thoughts? Input? Questions?

Again Thanks for all the help.
 
#11 · (Edited)
You have the signals correct. The gear position switch sends a ground to pin 7 (7 wire) and this gets routed to pin 5 (10 wire) which feeds the dash to light the neutral light. Pin 9 (10 wire) gets the starter button signal (used in reverse) this signal gets passed from the RCU on pin 10 (10 wire) to the F/R micro switch that passes it to the starter relay when F/R is in F. So it sounds like you need to check the F/R switches they one will be closed and the other open in F and the opposite in R. Sounds like switch # 2 is staying closed.

Also pin 8 (10 wire) passes a ground to the engine electronics relay that is interrupted by the RCU when the neutral signal is not present and the side stand is lowered. Killing the engine in gear or preventing from starting in gear unless the clutch is pulled in

So if you confirm the operation of the F/R micro switches match what I said above then most likely you have a bad reverser unit. These do not fail often and usually their failure mode is a short in the output device and a melt down ensues. I snagged one on eBay for $35, it was listed as an audio amp probably because of the barrel connectors and three heave wires.

Yes I also agree that air heads are MUCH easier to work on.
 
#13 ·
So it sounds like you need to check the F/R switches one will be closed and the other open in F and the opposite in R. Sounds like switch # 2 is staying closed.


Today’s test results:
With the F/R switch in the F position I have an open circuit on pins1&2. I have continuity on pins 3&4.

With the F/R switch in the R position I have continuity on pins 1&2. I have an open circuit on pins 3&4.

Unless there is something else that comes into play I’m assuming that my bad RCU diagnosis is correct.

Please advise and Thanks again!

Scott
 
#14 ·
I have to agree. You did check that each of the three heavy black, with yellow stripe, wires from the RCU are connected correctly. Red sleeve to battery (+), brown sleeve to ground tie point and black sleeve to starter tie point. (as shown in photo in post #4)

If those are correct that just leaves the RCU.
 
#15 ·
Yes I’m 100% sure that those are correct. Again thanks for all of your help and everything that you’ve shared with me has been documented in my phone and on the wiring diagram in my Clymer for this bike. The replacement RCU will be here tomorrow and installed Wednesday. I’ll definitely report back.
 
#16 ·
I looked you up, neat shop. Next time I am up that way I'll stop in. That tunnel on 71 in Cincinnati was a bit slippery at the entrance, thought I was going to dump my LT.
 
#17 ·
Thanks. I’m a one man show. At one time I had 5 employees and 20-30 bikes going through the shop each month. I was miserable.


Now for the good news. The replacement controller did the trick. By end of business tomorrow I’ll have this bike buttoned up and ready to ship.

Thanks for all of your help and please do stop by if you’re ever in Cincinnati. Make sure you contact me first for the super secret address.
 
#18 ·
03 K1200LT. Gear indicator read out issue.

I got another K1200LT in. It’s in pretty good shape, I’m just doing tires and brakes and fluids. One thing the customer asked me to resolve is a false read out on the gear indicator. Gearing/Display is as follows:

1st reads 3
Neutral reads 2
2nd reads 2
3rd reads 3
4th reads 6
5th gives a blank read out
The neutral light works as should aside from being accompanied by 2. Otherwise this bike is in great shape 27,000 miles, all electrical and electronic functions are correct. I’d love some input before I go so far as to pull the cross member to access the gear indicator switch. Thanks in advance.

Scott.
 
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