Electrical Questions...

Battery negative measures 0 ohms between both frame & engine.

Forgot to measure green to ground; I'll get that after my job interview.

Green-brown jumper measured 10.78 VDC first time around. Fiddled with stuff for 5 minutes or so & left the ignition on, got 10.3 VDC on 2nd read. (Maybe just the headlight sucking juice?)

-Kit

Yes, the battery seems very low if that's a true reading. It shouldn't affect the tests I'm proposing as long as the bike will run. You may want to throw the battery on a charger if you have some time. You don't want it to go totally dead while testing.

Okay, got the green <-> ground reading: 4 ohms. Also, forgot to mention: holding a screwdriver about an inch away from the stator cover results in a loud click when the ignition is turned on. The magnetism pulls the screwdriver onto the case pretty strongly.

I'll charge the battery as soon as I get a chance. Seems like it's draining pretty quickly...

Thanks,
-Kit

Ok, good. Now we know the field coil is good. Next we need to decide between stator and rectifier.

Have you ohmed out the stator? If not, disconnect the three yellow wires from the rectifier and measure the resistance between each pair of wires. Then measure the resistance from each yellow wire to ground (battery post).

If it ohms out ok, we'll do a load test on the stator.

Resistance between each pair of yellow wires from the stator is 0.8 ohms, ignition on or off.

Yellow to ground is weird with the ignition off. It starts around 70 kilohms & moves up slowly but steadily. I'm guessing what we actually care about is the reading with the ignition on, which is infinite.

Thanks,
-Kit

Did you disconnect the three stator wires from the rectifier before taking the readings? If so, then the ignition switch should have made no difference in the ohm readings.

This forum is really annoying right now so I'll PM you with my email. I have to keep scrolling left and right just to read these posts.

Post edited by: loudhvx, at: 2006/04/04 23:26

Hey Lou:

I love the look of the new forum, but the functionality does leave a bit to be desired right now. I'm lucky to have a high enough resolution screen that it only affects a few threads for me. You mind if I post our email conversation so everyone can benefit?

I disconnected the 4-pole/3-wire connector from the rectifier & took my measurements from the contacts inside the stator side if the connector. I tested each wire to ground several times because I thought it quite odd that the reading climbed like that. After re-testing, it occurred to me that it might make a difference whether the ignition was on. It did.

Thanks again, man. It helps my sanity to know that this stuff that seems weird to me seems weird to someone who actually knows this stuff.

Cheers,
-Kit

The forum is working for me on my home computer. My laptop at work has a smaller screen so everything gets scroll bars. It didn't have a problem before so hopefully the bugs will get worked out.

That stator test was strange indeed. There's not really enough data to speculate why it behaved that way, but on to the next test.

For this next test you need a headlight bulb from a car or bike. Keep the stator disconnected from the rectifier.

Run the bike with the green and brown field-coil wires still jumpered. This means the alternator should be putting out maximum power. At idle, you should be able to light up the spare headlamp by jumpering to any pair of the three stator wires. Test all three possible pairs. If the bulb is dim, give a tiny rev to the bike. Be very careful. It will be very easy to burn out the bulb if you rev a little too much. It's AC power, but should still light up the bulb with no problem.

If you don't have a spare 55 watt headlamp, you could try a 120 volt bulb. I haven't tried it, but others have said it works. Maybe a 35 or 40 watt household bulb. I would expect it to be dim though, if it lights up at all.

Another test you can do is simply measure the AC voltage on the three pairs. The test doesn't show you a load condition, but I just remembered your rectifier shows no voltage even with no load, so this in your case, an open-load test may suffice.

Post edited by: loudhvx, at: 2006/04/05 11:39

The spare H4 box turned out to have a broken 1187 in it, but I managed to dig up a test light. It's marked "80-500VAC/DC". The test light does not light at idle, but does light when the bike is revved.

Straight voltmeter reading on the stator wires at idle is 39 VAC for all 3 pairs.

Thanks,
-Kit

That's a wierd test light. I don't really understand what it is. But, it did light up which means the stator does put out some kind of voltage under load. That means the zero-voltage-output result on the rectifier's output test is saying the rectifier is bad (as always, it can also mean there is a broken wire). I'd try to replace the rectifier.

Or you can also try to build one for about $15.
www.geocities.com/loudgpz/GPZdiy3phaseRectifier.html

Post edited by: loudhvx, at: 2006/04/06 21:50

Okay, did one more test today...

I jumpered the green & brown, disconnected rectifier's white, turned ignition on, & measured rectifier's white to battery ground. Zero voltage.

I then started the engine & checked again: 39 VDC @ idle.

I'm guessing that rules out a broken wire, does it also mean the rectifier is okay?

If the rectifier is fried, I'll probably give the homebuilt one a go. Any idea where I could find that 6-pin connector?

Many thanks,
-Kit

got a radio shack around there? goodluck,happy wiring!