'02 R1150GS Electrical Issues

65K miles and removed the fuel tank mid-winter to drain the old fuel. I've successfully had the tank off a number of times in the past but this time, after re-installing it, a few electrical issues emerged:
1. The ABS lights/mechanism has presumably failed. The lights remain on and the familiar "clunk" of the ABS activating when getting underway, has ceased.
2. The clock works/illuminates but "zeros out" each time I turn off the ignition.
3. My Battery Tender will no longer charge/maintain the bike's battery. It's a multi-terminal unit and is working fine with maintaining other batteries. . .

The bike starts and runs just fine and there's no indication that the charging system has failed. . .
I'm suspecting a failing/failed electrical loom/plug issue under the tank, involving the fuel pump, filter/sending unit.
Seems like I've read something in this Oilhead Forum around such issues but for the life of me, I can't find prior posts addressing this.

Thoughts/opinions/Forum guidance from my fellow Oilhead friends out there? Got lots of time to address such things now that I/we are all sheltering in place!!!

There are a number of threads in the “similar threads” section at the bottom of the page. It sounds like you are looking in the right direction.
OM

Beyond the Similar Threads, try searching the forum with google using the following search term "site:forums.bmwmoa.org R1150GS Electrical Issues". I did and found a few more threads that might be interesting. While not specific to your issue, there might be some ideas. One mentioned a load shed relay. Another suggested a weak battery. I suspect that the issue of taking the tank off and reinstalling might just be circumstantial.

I would start with removing the fuel tank and checking any visible connectors that may have been disturbed.

If that fails to resolve the issue then I would as systematically as possible identify everything that does work and everything that doesn't work.

With that information I suspect some of the real electrical wizards on the Forum can pinpoint the problem.

In the meantime, as always, check fuses and grounds.

Check Fuse F3 - 15A for issues 2&3

As far as issue #1 goes what is the mfg date of your bike? after the serial # xx/02

This will determine if you have ABS II or Servo type.
When it was running properly, did you hear motors under the tank when the lever/pedal was actuated?

Assessing/Diagnosing Electrical Issues

I'll give F3 a check AND I'm gonna look more closely at that undertank connector, scrutinizing for any broken connections/exposed wires. I'm thinking removing the tank in cold weather equals stiff plastic, which may have been my enemy at the time.
And I'll dig up the VIN shortly but do not ever recall hearing servos spinning along upon start-up. Only that familiar "clunk" as the bike first rolls. Then, the simultaneously flashing ABS lights extinguish. Again, the bike runs just fine and, moreover, there's no indication that the system is failing to charge.
Thanks for all for your input and stand by. . .

marblehead said:

I'll give F3 a check AND I'm gonna look more closely at that undertank connector, scrutinizing for any broken connections/exposed wires. I'm thinking removing the tank in cold weather equals stiff plastic, which may have been my enemy at the time.
And I'll dig up the VIN shortly but do not ever recall hearing servos spinning along upon start-up. Only that familiar "clunk" as the bike first rolls. Then, the simultaneously flashing ABS lights extinguish. Again, the bike runs just fine and, moreover, there's no indication that the system is failing to charge.
Thanks for all for your input and stand by. . .

Click to expand...

If you hear/heard a clunk the bike is ABS II. That's a good thing.
Do you have access to a GS911 scan tool?

With ABS2, all three symptoms could be caused by a failed battery - or a bad cable connection to the battery. Pull the battery out and try charging it. Put a meter on the battery and check the voltage. What happens to the voltage if you connect a headlight bulb to the battery? Take it to a shop and have it load tested.

How old is the battery?

Resolved!

F3 it was and oh boy, those filaments are tiny, tiny, tiny! Couldn't tell with my first inspection but ruling out a failing battery or charging system, I went back to the fuse panel and looked closer. Easy, inexpensive fix and the ABS, clock and Battery Tender charging are all now happy. And so am I! Thanks, everybody, for your collective wisdom and counsel. Looking forward to pudding the COVID-19 Pandemic in my mirrors but only when appropriate!

Always use a ohmmeter to check a fuse.
Many times visual won't show an issue.

Good news.