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Got it. No attempts at starting the bike and voltage will steadily drop down as low as 10v with no intervention from you at all. The wiring diagram above shows the components controlled by the 10A fuse. The two idle actuators, the ABS module, starter relay, fuel pump and flapper valve, for a total of 6. The starter relay isn't likely the problem because it's working and you replaced the main relay. If you disconnected ALL the others, then try the handlebar connections. It seems really unlikely, but one could be stuck. You could check them with an ohm meter, or disconnect under power as the others. The only component I see that can draw heavy current is the fuel pump and you already tried it. Do you have the ability to isolate individual wires? Pulling them out of the connectors? Because now, I think you're looking for a bad handlebar switch which probably isn't drawing that kind of current, a wire rubbing metal somewhere, or the ECU itself. If you aren't sure you got the idle actuators, try disconnecting the small connector from the ECU and you'll get them both. How long from key on till volts drop below 12V?
Do you think an idle actuator drawing that amount of current would be noisey or even smoking? Must be a lot of current flow with those voltage readings
 

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Discussion Starter · #22 · (Edited)
@IanHoots thanks on the alternator diode. As for drawing constantly, this draw does seem to be constant, it only stops when the main relay opens the circuit. I have not disconnected the alternator yet.

Yes when I pull the 10amp fuse, the draw is not there, which is why I am pretty sure the problem is on that circuit. As for starting with the 10amp fuse out, it cant because the starter is on that circuit.

As for the idle actuator drawing that amount of current itself, I dont think so.. but I am disconnecting components one by one just to try an isolate the problem. My guess is that it is a short, bare copper wire on frame, that is causing a draw this strong, that doesn't make any sound. But that guess is mostly because thats what I have seen on my bikes before. I have thought about shooting around with this thermometer gun looking for high temps.. but really hoping that disconnecting something is going to isolate it to a single component and its wiring.
 

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1998 R1100GS,2017 R 9 Racer, 2004 Moto Guzzi V11, 2004 Triumph Thruxto
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@rich46 thanks for the info on the voltage spike. that's interesting.
Hello Winston. Just a wee bit more. The Rep (do keep in mind that IMHO rep and salesman are quite similar) told me that when you turn on the key switch that excites the battery. The electrons begin to move faster and in 30 to 60 seconds they will be up to their max. Not totally trusting I removed a battery from a proper lithium battery charger and let it rest over the night. In the morning it had 12.8 volts. Placed in the motorbike and connected (was a race bike with out even a charging circuit) and retested after after about 1.5 min. it took to install and test the multimeter read 14.1 volts. Not a perfect test and there could be other factors but that's what we saw on the meter.
 

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@IanHoots thanks on the alternator diode. As for drawing constantly, this draw does seem to be constant, it only stops when the main relay opens the circuit. I have not disconnected the alternator yet.

Yes when I pull the 10amp fuse, the draw is not there, which is why I am pretty sure the problem is on that circuit. As for starting with the 10amp fuse out, it cant because the starter is on that circuit.

As for the idle actuator drawing that amount of current itself, I dont think so.. but I am disconnecting components one by one just to try an isolate the problem. My guess is that it is a short, bare copper wire on frame, that is causing a draw this strong, that doesn't make any sound. But that guess is mostly because thats what I have seen on my bikes before. I have thought about shooting around with this thermometer gun looking for high temps.. but really hoping that disconnecting something is going to isolate it to a single component and its wiring.
If you have access to one, a thermal image camera is a quick way to find a short in wiring.
I might be thinking about this back to front. Is the 10amp fuse in the wiring diagram you posted the fuse in question? It looks like that fuse supplies the solenoid side of the main relay. If you pull the fuse the relay opens? Could you remove the relay, jump the 87 and 30 terminals and then test for current draw on the circuit that the relay switches on? I may have it back to front, kind of need to lay my hands on the bike to follow it around in my head.
 

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Sometimes a ‘power probe’ is handy for this sort of work as you can bypass main circuits and poke power into the starter solenoid and still start things.
 

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have tried using a amp meter instead of a volt meter?

Trying to determine with a V-meter what is happening to the current (A) is not very reliable.

With the A-meter you can test each wire to see what current runs through it...
 

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Maybe test the battery itself or it holds a charge.. so disconnect it and check it just after you rode / the next morning.

I have (although it's rare) seen that people replace one bad battery with another bad battery.
Then they assume the battery is fine; but it's not.
 

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Discussion Starter · #29 ·
Thanks a ton for the feedback.

@rich46 thanks for elaborating on the voltage spike.. I find that strange and confusing.. have never seen anything like that. but I wish my bike spiked.
@IanHoots I like the thermal camera idea a lot.. I will study that wiring diagram and try to understand what you are thinking.
@Tigcraft yes I do have a probe tester, but have not used it so far. Hoping to isolate by unplugging.
@Chopper_Bob I do not have an ammeter on hand.. if I unplugging a component stops the draw, I suppose I could insert an ammeter or test light into the circuit there to measure.
@Lelc2 good idea about the heated grips. I did use them a few times lately, but this problem started in hot weather. As for length of rides, typically 20-30 minutes to. 1 hour.
@Chris. when I first started to troubleshoot, I would put the meter on the bike as soon as I parked.. and measure it on the hour until I went to bed, and then check in the am. Did this for days. I never saw any kind of loss. Always dropped very slowly to the resting point around 12.8. Then I started testing with the key on and found the draw. Since I have had both batteries load tested and because this testing process taps the battery, I put it on the 2amp charger after running the tests. As I added up top yesterday, by the 5th test, which is simply turning the key on, leaving it for a few seconds, not touching the starter button, and turning key off, the voltage was dipping into the 10 volts. Within 1 minute of being off, it was back up to 12.7, but at that point, I put it on the 2amp noco and let it top off, within less than an hour, its on float charge.
 

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Discussion Starter · #30 · (Edited)
If anyone is inclined to humor me and try this test I have been running on YOUR bike, I would be interested to know the outcome:

I have the tank up and the fuel pump disconnected so I can clip directly to the battery, but that said, I get the same results if I jus take the seat off and clip to the positive bolt at where the seat meets the tank and the negative bolt on the underside of the right head.

1. With the bike cold, preferably over night for the first test, I see the voltage.
2. I insert the key and, watching the voltmeter, turn to on- I do NOT touch starter button.
3. Watch the gauges cycle, hear the fuel pump and flapper servo (if you still have it) cycle, then wait 5-10 seconds after all is quiet, watching the meter.
4. Watching the meter, turn the key to off, and pull it out to make sure. At exactly 1 minute after turning key off, hear/feel servo and main relay open, voltage jumps, and then slowly rises back to resting voltage, within about 1 minute.
5. Repeat 5x, not waiting overnight between each test, just a few minutes, long enough for the battery to rise back up resting voltage of say 12.7 to 12.9

What I am interested in knowing, is the range of the voltage dip. On the first test, mine starts at 12.8 and dips to 12.4 or 12.3. By the 5th test, mine starts at 12.7 and dips to 10.5 volts.
 

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I'm starting to think the focus may be too narrow. The 10A fuse is the main power fuse so pulling it will kill power across the motorcycle, but when you have the key on, you have power going to everything but the headlight, so the whole electrical system is active.. You may want to look at the wiring for the whole bike and try disconnecting the rest of the fuses one at a time and see if you get somewhere. Do this with the key on. You can buy some more battery time by hooking up your second battery to the first, positive to positive and neg to neg. That will share the discharge between the two.
 

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Discussion Starter · #32 ·
@gene_apodaca thanks. I actually just confirmed that as someone else had asked, when I pull the 10amp fuse and turn the key on, nothing happens and there is no change in voltage, so I am with you on that one. As for pulling other fuses, the only other one I know of is the 4amp fuse.. and pulling that doesn't not affect the voltage drop. The bmw pocket user manual only mentions these 2 fuses.. are there more?
 

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All I can think of to isolate circuits would be to go to the wiring diagrams and disconnect stuff. If a wire is chafing, you can maybe find it with a thermal scanner or by looking. If you can pull pins out of connectors, disconnect the red ones.
 

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Interesting problem you got there.... Now call me crazy, but isn't everything on these bikes canbus?
Instead of blown fuses we get canbus to shut down circuits. Have you tried checking for logged events?
 

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Winston, Being a simple guy I'd first take my test light and go through all the accessories and switches (side-stand,horn,turn-signals) to see if anything is hot that should not be with the key off. I'd then pull apart the switches so I can get to the small circuit boards and do the similar test. I have had the same issue with a Honda Goldwing and a Kawi touring bike and found the trouble there; the result of a wire being chafed by electronics without proper install by the owner. Something is drawing electrons from somewhere so I always start with the most easy to repair. If the trouble is there you replace or repair a wire or switch takes less time and will most probably cost the least. If the trouble is within the more complex components then go with God and good fortune.

With things such as wiring troubles remember the old adage "when you hear the sounds of hoof beats look first for horses not Zebras " I only say this because your trouble seems rather simple in that your battery is not crashing, there's no smoke and the wrenched thing starts from time to time. Now it may be some demon in the ECU but at least hope not.
I have had one faze of the starter motor go bad from time to time so when the starter is in one spot the thing will not start or is hard to start; put the motorbike in gear and bump the thing a bit against the Bendix and try again and off you go. I don't even know if this is even relevant in modern motorbikes and one would think you'd be getting some proper error message on the clocks if this was the trouble but it's a thought.. :unsure:
 

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The more I read your original post, the more I think the exact 1 minute opening of the relay is CANBUS shutting down.

Does your wiring diagram have other modules than the DME (engine control) listed? Something like a chassis control unit? I think that's a term used on old BMW bikes for the CAN BUS unit that turns most stuff like indicators and brake lights on and off.

I don't know enough about the wiring and don't have a diagram easily accessible.

CAN BUS control units do have the ability to draw a lot of current they turn stuff off if overloaded/shorted. Hence the lack of fuses.
 

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Heat grips?

You ride Daily but how many kilometres? Engine get enough revs?. Probably battery is not able to charge properly in this situation and get weaker and weaker...
Good guess but the alternator starts charging at very low RPM’s … I don’t believe that is the issue … I’m inclined to think direct short to ground as in a worn or bare wire that’s shorting out …. 10A is a load ! ………………..Blitz
 
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Hi Winston,
when you are performing the test , do you recall how long the ignition / 10 a fuse is live total time in minutes to reach 10 v from 12.87, ,
It is possible to measure the actual current drawn by measuring the voltage across the fuse,
there is a calculation matrix depending on type of fuse, i use an amp hound when checking muliple fuse boxes to save time,
out of interest what other additional electrics are added and how are they powered/ controlled
have they been in use when the bike intermittently fails,
what journey times frequency in the days before the non start,
what battery voltage is displayed when the non start occurs without cranking ,
apologies for the questions, trying to help,
Forest
 
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