Less than 1 volt drain on battery

[omaharj]

81 650 GL Stock electrical/mechanical. Left to sit for a week it lacks juice. Checked battery after charging and a few times after riding-12.7-12.8. When running @ 4500 RPMs I get 14.7 to 15 volts. I disconnect positive from battery,test between battery and unhooked positive and get a reading of 0.9 volts. Started pulling fuses one at a time. It's in the main fuse(The one in the middle).I've tried hunting it down by guess work. Guess what? still guessing. Is this something I should just let go and let the battery tender deal with or can someone steer me on a logical course? From my sig you can see I'm at my wit's end. Help! I can accept "live with it" as help.[-o< [-o< [-o<

[DaveDanger]

You may be doing this already, but make sure you're performing that check with the key in the off position. Assuming that you get that voltage drop with the key in the off position, continue following the wire circuit through that main fuse until you reach the culprit. I personally would not allow an electrical drain of that nature to continue. It will at the very least kill every battery you ever install in your bike, given time. At the worst, it could turn into a major electrical problem, possibly even shorting into an electrical fire. GS's don't make pretty bonfires. There's not a huge number of things that that circuit can feed. Take the time to track it down.

[Boondocks]

The only hot wire going through the main fuse with the key off is the wire to the key switch. I've had this one short out and blow the main fuse. You have a "slow leak" with not enough current loss to blow the fuse.

This wire runs through the main wiring harness under the tank. With the tank removed and using the same voltmeter test connection, wiggle the harness to see if this causes the voltage to drop to 0. Inspect the harness carefully for rubs through the insulation. Sometimes a sharp or abrasive metal surface or cable will eventually wear a spot in the harness and cause a short.

It's possible to get a short at the ignition switch itself. I have had this happen, and could see elecrical arcing like static electricity coming from the keys on the keyring to the handlebars. Shooting WD-40 into the switch seems to have cleared out the crud/moisture that was causing the electrical problem. The switch problem that I had was happening with the key turned on, so this may not be helpful to you.

[jimg]

81 650 GL Stock electrical/mechanical. Left to sit for a week it lacks juice. Checked battery after charging and a few times after riding-12.7-12.8. When running @ 4500 RPMs I get 14.7 to 15 volts. I disconnect positive from battery,test between battery and unhooked positive and get a reading of 0.9 volts. Started pulling fuses one at a time. It's in the main fuse(The one in the middle).I've tried hunting it down by guess work. Guess what? still guessing. Is this something I should just let go and let the battery tender deal with or can someone steer me on a logical course? From my sig you can see I'm at my wit's end. Help! I can accept "live with it" as help.[-o< [-o< [-o<

I'm not sure what you are measuring with your description. This isn't a good way to use a voltmeter. The reading could mean anything depending on just how your voltmeter is made. The fact that you pull the main fuse and the reading goes to zero, is the same thing you would get if you just connected one voltmeter lead to the battery. The other lead is, in essence connected to nothing.

What you need to do is hook it up just like you said, only put it in 'ammeter' mode to see what current draw there is. You could have as little as .01 amps, i.e. an LED causing a current draw or as much as several amps. Your battery could run an LED for months without discharging.

Also, as mentioned above, make sure your key is in the off position.

[DaveDanger]

Agreed to a point jimg... the only piece of information that you're getting with your voltmeter in this setup is the fact that you do have a drain on your battery with the key in the off position. And as far as I'm concerned, that's all that's needed to know. The amount of voltage or amperage isn't important. The fact that it's drawing is the info that's important. You could get the same info with a continuity light, or a circuit tester. If you make a circuit or get a continuity light, you have a problem that needs tracking down. When the main fuse is pulled and the problem goes away, all that tells you is that the problem is further down that circuit. Put the main fuse back in and keep chasing that wire. Keep disconnecting plugs or connectors until the draw or short is located. Fix it

[omaharj]

. When the main fuse is pulled and the problem goes away, all that tells you is that the problem is further down that circuit. Put the main fuse back in and keep chasing that wire. Keep disconnecting plugs or connectors until the draw or short is located. Fix it

That looks like the only course I can take ,huh? Thanks guys. BTW symptom is with key off. I WILL check ign. switch first hoping for luck.[-o< [-o< [-o<

[earlfor]

I would remove the fuse block and pop the back off of it first. I've seen quite a few with corrosion build up in the internals.

Earl

That looks like the only course I can take ,huh? Thanks guys. BTW symptom is with key off. I WILL check ign. switch first hoping for luck.[-o< [-o< [-o<

[omaharj]

Thanks Earl,will do. From above it looks clean but I'll check it all. That's TWO things to check before pulling the tank and possibly shredding my harness. (I will try to be careful):-|

[Boondocks]

I'm not sure what you are measuring with your description. This isn't a good way to use a voltmeter. The reading could mean anything depending on just how your voltmeter is made. The fact that you pull the main fuse and the reading goes to zero, is the same thing you would get if you just connected one voltmeter lead to the battery. The other lead is, in essence connected to nothing.

What you need to do is hook it up just like you said, only put it in 'ammeter' mode to see what current draw there is. You could have as little as .01 amps, i.e. an LED causing a current draw or as much as several amps. Your battery could run an LED for months without discharging.

Also, as mentioned above, make sure your key is in the off position.

On a vehicle like a car that has some circuits always active the measurement of current draw is useful to quantify any excess over the baseline. On this bike unless there has been some modification, with the key off the battery should be "connected to nothing". We know there is a severe problem with battery discharge. Unless the battery itself is bad and self discharging there has to be a significant current leak. I think that the voltage test was OK to indicate a problem, but then I would probably switch to amps/milliamps to see the current draw as you suggested.

omaharj, earlfor is giving you good advice. Before he posted, I was going to ask you to pull the accessory fuse first before doing anything else. It's the only thing in the fuse block that's hot all the time through the main fuse. Even though you may not have any accessories connected, corrosion in the back of the fuse block could bleed off current. Yes, I've had this problem too.

[jimg]

I checked my circuit diagram on my 80 550E, no guarantees yours is exactly the same. I show three things connected all the time, the accessory fuse, the ignition switch, and the rectifier/regulator. If pulling the main fuse solves the problem, then the only components that could be causing the problem is the rect/reg or the ignition switch. You could also have corrosion, spider webs, etc. in the fuse boxes or ignition switch as mentioned above.

I'd pull the connections on the rect/reg first and see if this stops your indication then move on to the ignition switch connections. Actually, checking behind the fuse box isn't too hard either.

[argonsagas]

My first action would be to disconnect the Regulator/rectifier. If that stops the problem, the red wire runs to/from the battery, the black is ground, and the other three all go to the sator, although one likely has a junction in the harness that runs up to the headlight.

You already know the stator is putting out sufficient voltage, so if removal of the R/R solves the problem, replace it.

Earl's point about the fuse box is very good...Even though you cannot see it, corrosion does build up in there. I had one box partly melt due to the heat buildup from internal corrosion.