Electrical gremlins affecting indicator lights and starter circuit

[eldevigo]

Howdy folks, I just got my project 83 1100E to start up again after I un-fixed it when I got it back from the mechanic last year
I'm still dealing with some electrical issues though. I thought I was halfway decent at reading a wiring diagram, but the diagrams in the service manual are not helping me here, maybe I just don't know what I'm looking for in them...

My main issue is that intermittently, the starter circuit in the bike goes dead. As in, I'll be out working on it, cranking the engine one minute, then stop to tinker something mechanical like idle screw, and when I come back to press the start button again the circuit stays cold, no clicks, no cranking.
When this happens it usually stays this way for a while, but fixes itself on its own if I leave the bike alone for a while. It definitely feels like a short somewhere, but I'm not sure where.


When the starter circuit isn't working, the ignition timing and headlight circuits still work fine.
I can tell the ignition is okay because I installed the recommended relay bypass mod, and I can still hear the installed solenoid click when I flip the kill switch or main ignition on and off.
I've also noticed that often when the starter is misbehaving, all the indicator lights on my instrument panel are lit up like a christmas tree. I can't seem to find any clues in the service manual about how the indicator lights are controlled - is there a central control module for them that might be misbehaving? or is this a clue that there's an issue that's affecting a bunch of independent circuits all together?

[eldevigo]

I know someone's first response is going to be "check your ground points", which is a very reasonable response. I've checked the main ground jumper from the battery to the frame, no issues that I can tell. I'll disconnect/clean/reattach it just to be sure though.
Are there other standard grounding points I should be checking?

[oldGSfan]

Howdy folks, I just got my project 83 1100E to start up again after I un-fixed it when I got it back from the mechanic last year
I'm still dealing with some electrical issues though. I thought I was halfway decent at reading a wiring diagram, but the diagrams in the service manual are not helping me here, maybe I just don't know what I'm looking for in them...

My main issue is that intermittently, the starter circuit in the bike goes dead. As in, I'll be out working on it, cranking the engine one minute, then stop to tinker something mechanical like idle screw, and when I come back to press the start button again the circuit stays cold, no clicks, no cranking.
When this happens it usually stays this way for a while, but fixes itself on its own if I leave the bike alone for a while. It definitely feels like a short somewhere, but I'm not sure where.


When the starter circuit isn't working, the ignition timing and headlight circuits still work fine.
I can tell the ignition is okay because I installed the recommended relay bypass mod, and I can still hear the installed solenoid click when I flip the kill switch or main ignition on and off.
I've also noticed that often when the starter is misbehaving, all the indicator lights on my instrument panel are lit up like a christmas tree. I can't seem to find any clues in the service manual about how the indicator lights are controlled - is there a central control module for them that might be misbehaving? or is this a clue that there's an issue that's affecting a bunch of independent circuits all together?

First thing I'd do is to isolate it, go directly to the starter solenoid and jumper it when it's giving probs. I think there's a 'brain' but like mine, I'm not sure how it works.

[rphillips]

My first thought the clutch switch, a common problem with GS's and way later Suzuki's. . Sometimes my Bandit won't do anything, then I push the clutch lever down while pulling it in, and it starts fine. I should go in there and adjust it, it just hasn't got that annoying yet.

[eldevigo]

OK, I ran my battery out this morning testing the idle and making sure it started reliably, and I don't have a jump pack handy so I'm waiting for it to trickle charge right now before I try to start it again for testing purposes.

However, I poked around the bike a bit more with a multimeter to see what I could find, and I learned some interesting things:

When the bike is off (at the ignition), the continuity between the ground of the starter solenoid and the bike frame is good, like you'd expect.
When the bike is on, and the starter is working properly, this is also true. I noticed this earlier, before the battery ran down.
However, when the bike is on and the starter circuit is *not* working properly, this circuit is *open* - no continuity. Flipping the key off and on causes the circuit to open and close - closed when the bike is off, open when it's on. This would explain why the starter won't start, but I'm not clear on what causes the circuit to open.

The wiring diagram in the service manual shows that the starter switch circuit should run straight to ground, and it seems to me that that's what I would expect it to do.
I traced the lead from the solenoid ground terminal, and indeed it does not go to the bike frame, it plugs into a black-and-white wire in the harness.
It looks to me like it passes laterally across the harness and straight out the other side though, as there's a similar black-and-white wire that pops out the other side from under the harness wrapping, and plugs into a rubber-sleeved control circuitboard that's hooked on to the bike frame just above the starter solenoid.
Testing continuity from ground to the black-and-white wire terminal on that PCB showed exactly the same behavior, so I'm pretty sure that's where the solenoid ground is going.

I'm still not clear on why turning the ignition on is causing this circuit to open *sometimes*, why it isn't other times, and what that PCB is for. There are about five other wires running into it from the wiring harness, it looks like some kind of control board and I suspect it may be connected to the unexpectedly illuminating indicator lights.

Anybody know what this thing is called, and how I can check if it's even the right one for the bike? This bike's PO replaced a lot of parts with whatever junk he had on hand, many things don't exactly match.

IMG20250918140842.jpg

[eldevigo]

My first thought the clutch switch, a common problem with GS's and way later Suzuki's. . Sometimes my Bandit won't do anything, then I push the clutch lever down while pulling it in, and it starts fine. I should go in there and adjust it, it just hasn't got that annoying yet.

I checked this btw, this bike doesn't even have a clutch switch. It looks like PO took it off.

[eldevigo]

My hunch is this gonna come down to the ignition. PO replaced the front end with one off a '96 Katana (he said), and the ignition got swapped as well - maybe the original didn't fit any more.
The current one is off a Kawasaki (based on what my locksmith told me) and it's *zip tied on*. I suspect it may not be connected quite right to the bike circuitry. The starter may be wired in to a circuit for one of the indicators, maybe the oil pressure light or something.