Need some help (what's new?) troubleshooting the regulator

[Damn Yankee]

After spending the better part of summer troubleshooting ignition and carb demons on this 15-yr-old bike, another demon rears its ugly head: The battery is not recharging. I am trying to follow the steps in the shop manual.

With a multimeter, I determined there is a battery current leakage of .05 mA--the max should be .01 mA.  Ok, then, on to the regulator. I can get a battery voltage reading for the battery charging line.But when I try to get continuity readings for the ground line and resistance for the charging coil line, I get no readings at all.

I am touching metal-to-metal with the 3-pin and 4-pin connectors (wire harness side) between the battery and the rear fender. I believe I am touching the proper wires for the test. The battery is fully charged at or above 13.0 V.  The multimeter wires are attached to the proper terminals for resistance readouts. The 9V battery in the multimeter is good. I switch around to all possible relevant settings. Nada.

What am I doing wrong?

Also, how do you test the rectifier to see if it's good or bad? I'm looking at the procedure on pg 15-8 and its a head scratcher;  Do I need a different multimeter (SANWA? KONA? WTH?)

Help out the knucklehead!

[LIMagna]

I don't think I was able to get proper resistance readings either.  I'm pretty sure I did remove the stator connector and check the voltage going into the RR with the engine running and all three coils where within spec.  What matters most is the voltage your seeing at the battery with the engine running.  It should increase a bit (somewhere between 14 - 15 volts tops) with RPM up to about 4-5K and then drop off a bit.  If you see much higher or lower numbers, the RR likely needs replacing.  Also be sure to check when the engine has been thoroughly warmed up as mine seemed fine on a cold engine but then output would drop down to like 12 volts max after the engine warmed up. 

[Damn Yankee]

Straight up volt check with all connectors in place @ 3,000 rpm : 13.1 volts. Should be within 14 to 15.5...
All connectors have been cleaned. Will also double check wiring for any bare spots,etc.

[guywheatley]

About three years ago I also pulled my stator and checked it according to the manual (or so I thought.) Good multimeter, good battery, no resistance. I determined the stator was bad.
On a whim I sent it to a wrenching session with a friend for one last check before I bought a new one. The smart guys checked it and said it was good. I stuck it back in, replaced the battery and haven't had a problem since. (Actually I just replaced a battery again, but that is because I'd swapped the good one out to another bike)
Any way, the point of this long ramble is that unless you really know what you're doing, (ie have done it before under supervision) it's easy to misdiagnose the stator. I'd take it to a shop, or a wrench session before I replaced it.

[Cadmandu]

I have been dealing with this issue for a year now. Melted connectors twice. Here is my soultion.
http://roadstercycle.com/Shindengen%20FH012AA%20Regulator%20upgrade%20kit.htm

[lragan]

In checking the stator, there should be three wires.  Test the resistance between them in pairs.  Then make sure that the resistance to ground of each leg in the triad is high.

On my bikes, the fenders are made of plastic.  They do not conduct at all, so touching one lead to a fender will always show high resistance.  The first gen bikes may be different, I don't know.  I suspect, and someone will surely correct me if I am wrong, that they are metal coated plastic.  It may be very difficult to get a good connection to this thin metal.  In any case, if you are checking resistance to ground, find a good ground connection on the frame somewhere, preferably where the battery grounds.

Thanks, Cadmandu, for the link to the MOSFET regulator.  Under light load conditions, it should dissipate considerably less power, and therefore not get so hot, as the stock units.  On the other hand, MOSFETs are typically more temperature sensitive, so there may or may not be a net gain in reliability.  Now if some enterprising engineer would just figure out how to replace the series diodes with FET devices, we could have a regulator/rectifier that was efficient under all load conditions.

[Damn Yankee]

Sorry, forgot to mention: This is a '95 3rd Gen. Almost 40-K miles. I've been using the frame or the negative lead for grounding purposes.

Took the R/R off the bike and brought it to the local Honda shop.They said it trying to measure the resistance is an unreliable way to see if it was cooked or not (???) They said they only way was to measure the output of the stator.  $90/shop hour, please. No thank you.

This blows.

[whisperer]

Short of wiring problems (read that again), the Honda shop is right. If you put the stator on a scope and the AC output is good, then the R/R is the problem. The other common way to troubleshoot this would be for a shop to throw a known good R/R on it (jumper to ground and plug the harness in). If all works correctly then they can sell you a new one and install it.

With all the R/R issues with Magnas (mine's fixed now but mine included) it would be very cool to have a MOOT R/R, a donated known good used take-off to send off to the next guy to plug in and try.

[Chad in Michigan]

read this thread. I had mine die in the spring and these were my findings.  
http://www.magnaownersoftexas.com/forums/index.php?topic=3550.0