Quick question

[the108penguins]

ok so I've checked the two connectors that come out of the stator and they are both within manual specs. I've also checked the reg/rect and that is within manual specs. the old ones were not reading properly. I checked them with two different meters.

[crazy steve]

ok so I've checked the two connectors that come out of the stator and they are both within manual specs..

Did you check each wire to ground? If any of these are going to ground, they can still read good between the wires but won't work properly.

[the108penguins]

you mean to check for continuity to ground?

[crazy steve]

you mean to check for continuity to ground?

Yes, exactly....

[cywelchjr]

That and do remember that the charging system does NOT provide enough voltage to charge at idle, but I have run mine at idle for 30 minutes or more without the battery running dead, so you might have something drawing too much, or the battery isn't really right (if it's not the right one it might just not have enough capacity).

[the108penguins]

The battery I have is 50N18L-(A3) I'll check for extra loads and see if I can find something. It's driving me NUTS!!!

[cywelchjr]

The battery I have is 50N18L-(A3) I'll check for extra loads and see if I can find something. It's driving me NUTS!!!

Sounds like the right one. What is the voltage at the battery when idling? Should be around 12.5, if it's lower you may have something sucking on it two hard. With a good fan I would be interested in what it does at 2500 to 3000 RPM.

[the108penguins]

ok so I am stumped. I'm pretty clueless when it comes to 12v electrical. I'm not even sure where or how to test for loads... I'm still at it but I am about ready to take it to an bike electrician and see if they can find the problem.

[crazy steve]

Well, what kind of meters do you have? If we know what capabilities you have for testing, that would help. All meters aren't created equal, so if you're not getting good info you'll be going in circles...

Post a pic or pics of what you're using...

[cywelchjr]

ok so I am stumped. I'm pretty clueless when it comes to 12v electrical. I'm not even sure where or how to test for loads... I'm still at it but I am about ready to take it to an bike electrician and see if they can find the problem.

Ok, so what's the voltage at idle? I know you said it was good at 3000, but the idle numbers are important too.

Oh, and what's the resting voltage (when the key is off when it's known to be fully charged). I'm truly wondering if the battery was properly prepped. I know there is some debate, but generally if the battery was not charged per the instructions included with it for the recommended time, it might test good, but not actually have it's full capacity and go dead quickly at idle.

Most lead acid batteries are at 80% charge right after the acid is added to them. The ones I have worked with, recommend 4 to 6 hours of charging at 2 amps before putting them into service. If you have a fan that puts out a lot of high speed air, I would recommend trying running it at 3000 RPM for a while (with the fan blowing on it from the front) and see what the voltage does. Even with NO charging system working at all, I could ride mine almost 20 miles each way to and from work and be able to charge it overnight for the next day while I waited for a replacement Reg to arrive. So even with normal load and a non working alternator, you should be able to idle it for quite a while with no problem. This is really sounding like a battery problem (maybe having been made worse by a previous charging problem) at this point.

Lets go with basic DC system theory here. If your getting full charging voltage at the correct revs, and the battery still goes dead, it's pretty much got to be the battery, as the only way you can get the correct voltage under load is for the charging system to be putting out the correct amount of current. It's basic electrical theory, to get a certain voltage with a given amount of draw requires that the charging system MUST be putting that much out. This is why the testing of a charging system is done by voltage level, and they don't bother with trying to test the current level. To test for max current level you make sure that much is being drawn, and measure the voltage, if it's still it spec then your getting the full draw of the system as it should.

I know I've said a lot here, but here it is in a nutshell. If your getting full charging voltage at 3000 RPM (neither over or under, both are equally bad), and it maintains, then the charging system is good. If the charging system is good and the battery is going bad, the problem (unless it's going dead with the bike off, in which case there MIGHT be a partial short somewhere) is the battery, regardless of how the battery tests out.

[the108penguins]

the resting voltage tests at 13.2 on my bike. I tested the battery in my truck and my car both known to be in good working order. With the vehicles off the meter reads them at 12.7 and 12.8 respectively. On my bike the voltage reading at 1500 rpm is 14.2 which at the moment is the lowest I have it set to (I'd be able to finish tuning the carbs if the bike would run for more than 10 min)

I've checked for phantom loads while the bike was off and there is nothing. I have been able to charge the battery, leave it for a few days, come back and it's still held it's charge.

ok so here's a pic of my multimeter.

[cywelchjr]

the resting voltage tests at 13.2 on my bike. I tested the battery in my truck and my car both known to be in good working order. With the vehicles off the meter reads them at 12.7 and 12.8 respectively. On my bike the voltage reading at 1500 rpm is 14.2 which at the moment is the lowest I have it set to (I'd be able to finish tuning the carbs if the bike would run for more than 10 min)

I've checked for phantom loads while the bike was off and there is nothing. I have been able to charge the battery, leave it for a few days, come back and it's still held it's charge.

Well, the voltage sounds good at rest, certainly within spec, but the idle voltage sounds like it might be a little high. But even if the charging system was dead it should run more than 10 minutes. I don't know if that unit will do DC current without it being in line, but measuring what direction flow is between the battery and the rest of the bike and how much. It should be close to even at 1500, if not even. I ran mine close to an hour each way, daily for almost a week with the charging system not working at all, and while it was low when I got home, and I had to charge it overnight, but it went a lot longer than 10 minutes.

As for getting time to sync the carbs, if nothing else you should be able to hook jumper cables to it off the car to provide enough capacity to keep it running long enough to warm up and adjust them. But at this point based on voltage it should be charging not discharging. Are you sure your measuring DC voltage when it's running? What does it read on the car and truck when they're running? Clearly there is a problem, and it sounds electrical, but I'm at a loss at this point. I think you need to go through the troubleshooting steps in the shop manual, and work through that to find out what's going on, cause something sure isn't right.

[natemoen]

Says right on the enter Cy, "True RMS AC DC"

[the108penguins]

so from the sound of it the battery is a goner even though the tests say it is good.

[crazy steve]

You still haven't found the problem, so don't throw that battery just yet...

First, your meter. It should work, the only problem I see is it's rather high .1 ohm resolution according to it's specs when reading low ohm values, particularly if it's calibration is off any. So getting an accurate reading on the stator windings will be tough. The correct reading should be .4 ohm, with a range of between .36 and .44 being acceptable. This is beyond the resolution of this meter; so if you get a reading of other than .4 ohm, you may still have a problem with the stator.

But ignore that for now; even if the stator is a bit out-of-spec, the charging system should still have output. And like Cy said, it should run for more than ten minutes even if the charging system isn't working. So that really points at a low-grade short or failed component that's drawing too much current when the bike is 'on'.

The key to troubleshooting electrical issues is to isolate and test each individual component. And remember, a wire is a component too. Testing just the bits that plug-in may or may not fix it if the problem is in the wiring. Here's a few things I would check....

One, double-check your field coil between the green and brown wires for the correct 3.1 to 3.9 ohm 'range'. If you get a reading either above or below these numbers, the field coil is bad. Also check each wire to ground; if you get a reading to ground, the coil is bad no matter what reading you got between the wires. Note that if the coil is bad, you will still get output but it will affect the current output, not neccesarily the voltage. And if it's going to ground, it will suck the battery down.

Also check the brown wire coming to the coil. This can be isolated by unplugging the field coil, the ignition switch, and pulling all the fuses. Check this wire to ground; if you get any sort of reading, you need to trace this through the harness and find where it's going to ground. This could be be your 'extra' load that's running the battery down. While you have the ignition switch unplugged, check for internal resistance by checking between the brown, blue, and red wires with the switch 'on'; if you get readings above .2 ohms between any of these, you have a bad/dirty switch. Look in the achives for how to disassemble/clean this.

Isolate and test the ignition system; start with a fully-charged battery to do this. First, unplug the handlebar switch, and leave the ignition switch off. Connect a jumper wire between the positive battery post and the red/white wire that feeds the ignition system. You can do this at the fuse box by removing the fuse feeding the r/w wire and attaching to the fuse clip to goes to the r/w wire. Start the bike by shorting across the two large bolted terminals on the starter solenoid. If the bike runs for longer than the 10 minutes you've been getting, now you know the problem is elsewhere in the electrical system. If it again quits after 10 minutes or so, you may have a problem in the TCI box; a bad solder joint can cause this problem, or a component can be heating up and going open or shorting. You can also check for battery function at this point by connecting/jumping another battery to the bike. If the bike now starts/runs, you have a bad battery. If not, the problem is elsewhere.

Ran longer than 10 minutes? Ok, now disassemble and clean your handlebar switch to make sure you have no resistance through that. Also make sure the plug connections on all this stuff is clean. Every connection will use some power; get enough of them that are poor and it can add up. Be methodical; make sure each component/connection is good before moving to the next one. This can take lots of time, so be patient.

So to this point, if all testing has gone good you know that the charging and ignition systems are working properly and the battery is good. Reconnect everything, but remove the two fuses that feed the red/yellow and brown wires. Again starting with a fully-charged battery, start the bike. If it runs beyond the usual time, you now know the problem is with one of the two 'other' systems. Install each fuse one at a time and observe the results. If the problem comes back with one or the other, you need to go through and test each wire/part in that system until you find the bad one.