Charging system too much for my feeble mind

[Anonymous]

Hey guys,

Life hasn't been the same since my GS went sour. A while back she had trouble starting and then she started running bad and in short (haha) was showing signs of a failed charging system.

I'll skip the chronological-order story for now, but I'll tell you what I know and then maybe you can tell me what you know.

The RR: I replaced this one with a supposedly near-new one from Ebay. It sure looks new. Now, here's the thing - I do the diode test, and I get .5V in one direction, like the troubleshooter on this site says, and then I flip it around, and I get 0V. This is the result with all three diodes, with BOTH the old and new rectifiers. I did hook the new one up and take a ride, but I did this test before that and found this result. It makes me think I either have a bad multitester, two improbably bad RRs, or a hole in my head.

The Stator: I got a new one on EBay with the RR, the guy threw it in for $10, saying it was "untested." Well, it turns out it wasn't worth 10 cents, because the thing had visible opens in the circuit - huge chunks of wire missing. I guess it will be useful if I try to rewind a stator, but the thing is, my old one looks FINE. Now, when I tested the old one in the bike, I was getting like 10V, maybe 15V out of the loops @ 4500 rpm. I read it should be 60V, so I figured maybe this was bad too. I don't remember what the resistance readings were. Anyway, I have the old one out now, and it looks fine, and it reads 1ohm for each loop.

The problem is, when I had the new RR and the old stator hooked up before, I was seeing about 12.5V at the battery. Not enough to charge, right? So what's the problem? Dirty connections (I cleaned 'em with an emory board though)? The wires from the stator don't seem to be continuous with each other or ground.

I can't figure it out. This bike also has leaking intake boots, and flaking clearcoat. Anybody want an '82 GS1100GK project bike?

-Dom

[Guy]

The best way to test the alternator is to measure the AC voltage across each of the three coils. They should each read 75-80VAC at 5000 RPM. Trying to measure such a low resistance is pointless and will give misleading results.

[SqDancerLynn1]

It sounds like you were testing the stator for DC voltage?? It should be tested for AC voltage at 5K 70-80 vac Disconnect them from the reg when testing

[redliner1973]

Re: Charging system too much for my feeble mind

Hey guys,
Anybody want an '82 GS1100GK project bike?

-Dom

Where ya live???

[Anonymous]

Nah, I was testing AC. I know that sounds like it's in the DC operating range for 12v systems...just a coincidence. I don't really know what would happen if you hooked up a meter in vDC to an vAC source...prolly zero.

Thanks for the info on the resistance Guy...I don't know why that would be the case but you sound pretty confident about it so I'll buy it. If I discount the resistance reading...the vAC reading says my stator is shot. Which in turn means my RR is probably fine and I've wasted my money on that.

Any more good advice is much appreciated.

I live in West Virginia, near DC. For the right money I'll fix this bike's charging and you can ride it home.

-Dom

[redliner1973]

Another suggestion: this helped mine tremendously, that 1st connector that the stator wires go to, cut it off and solder them directly. mine looked 'good' to me, I cleaned them, etc, and still had low output. Soldered them and cured my problems.

[Anonymous]

I'll certainly check that out. The wiring at the stator was pretty fragile, I tore one by accident, so I've soldered those...I'm thinking of putting new wire through the whole charging system, soldering where I can, replacing connectors where I can't.

I wish there was some way to more reliably ensure good conductivity. Anybody know, by the way, how to get those little brass connectors out of the plastic harness bit? I'd like to replace them.

-Dom

[Redman]

Some Comments about the connectors:
- To get apart brass connectors ("bulett connectors" on stator) in plastic covers. Use two pair of plyers, grab the conectors right thru the plastic, twist and turn first to brake it loose but not enought to rip up the plastic. Then hold one connector with plyers at base, and with other plyers push back the outerside plastic cover (kinda folding it back - wrinkling it up) some to where you can then grab the other connector.
- But if you are intending on removing/replacing the connectors, dont worry about how you get it apart, just cut the wires as close to the connector (thru the plastic) as you can get.
- Problem with cutting off the connectors and soldering them together is that if that doesnt really fix your problem, then you cant easily take them back apart for further testing. One option is to cut off connectors and reconnect the wires with wire nuts (small gray ones) as a test to see if it works better, but yet you can still get it apart to test stator voltage output and/or RR ohm check.
- You have noticed that the wires are brittle. That makes me think that yes the connectors were bad, have been heating up, have effected the wires.
- Dont use crimp on connectors. These wires are too brittle for that, the crimp connection will loosen up in just a couple months.

[redliner1973]

The easy way to get the wires out of the connectors is to use a flat-bladed jewelers screwdriver, slide it down the front of the connector and push down the little tab on the metal part of the connector, then just pull it out. I do still feel that soldering the wires together, adding an external ground wire from your R/R to the '-' Battery terminal will cure most charging issues, short of a electronic-unit failure. Most troubleshoting can be achieved either before the wires are soldered initially, in like the case of stator testing, or can be accomplished through un-wrapping of the soldered joints to take a multimeter reading. Please note, however, that the connectors may look good visually, but be melted/corroded inside. The brittle wires around the connector confirm that resistance is in the connector.