Alternator Issues

[cywelchjr]

Ok, I've looked at all the tech articles and I'm a bit stumped. The alternator windings come out just slightly out of spec (1 ohm) and I was not getting lights (someone appears to have hardwired the headlight on) in the guages (did the first day I had the bike) and today the tach stopped working. The question I have is can the regulator cause this or is the alternator bad.

I'm guessing it's bad, but thought I would ask those with more experience.

[randy]

We need to know the model of your bike as the alternators differ between XS and XJ.

The short answer is yes, the regulator can cause that symptom, but so can other things. Update your signature to include the model.

OK, checked your profile, you have a 80G. Here's a quick check: turn on the ignition key and hold a feeler guage or some other light guage piece of ferrous metal (paper clip) near the alternator, it should attract. that means your field winding is working. With the field winding working, you should have output from the alternator. Next start the bike and measure the voltage at the battery, at 3500 RPM you should have 13.5-14 volts.

[fredintoon]

Hi Cy,
almost any small fault in the charging system will stop the power from being generated or stop it from getting to the battery. In my case it was a wire trapped under a bracket so that after a few months the insulation extruded off and grounded the power instead of feeding it to the battery. If I'd only checked the wiring first instead of last I wouldn't have bought a replacement rotor, stator and regulator/rectifier but hey, have I got spares for when I need them! Also, I have had a failed fuse connection stop the gauge lights, signals & tach working. Also had the connector with the 3 white wires in it a burn out to do the same.
And if the small plug-in under the tank where the tach connects to the harness fails, the tach will stop. Check out every little connection before spending the big bucks.

[cywelchjr]

We need to know the model of your bike as the alternators differ between XS and XJ.

The short answer is yes, the regulator can cause that symptom, but so can other things. Update your signature to include the model.

OK, checked your profile, you have a 80G. Here's a quick check: turn on the ignition key and hold a feeler guage or some other light guage piece of ferrous metal (paper clip) near the alternator, it should attract. that means your field winding is working. With the field winding working, you should have output from the alternator. Next start the bike and measure the voltage at the battery, at 3500 RPM you should have 13.5-14 volts.

Didn't do the feeler gauge trick, but did check for proper voltage diff across the field coil and field coil resistance is right on the money in spec. Voltage IS low, running about 12.5 or so at 3000 RPM, but I have not rechecked since the tach stopped today. I put it on the charger maintainer at night. I'll double check the connections to make sure that's not the problem, and try tracing down the rest to make sure before I spend on the other parts.

[bikerphil]

Most important

Check the connector with the 3 wht. and 1 yel. wire coming from the alternator as mentioned. It tends to corrode and overheat. It is located behind the fuse block mounting panel (3 phillips screws). HTH

[cywelchjr]

Check the connector with the 3 wht. and 1 yel. wire coming from the alternator as mentioned. It tends to corrode and overheat. It is located behind the fuse block mounting panel (3 phillips screws). HTH

I did check that connector and everything looks nice and clean.

[randy]

If your connections are good, and your field coil and stator are good, replace the regulator.

[strom]

Maybe something similar, maybe not....

Tach was a bit wobbly from when I got the XS 1.1 standard (euro.. G i think in US)... especially in 4-6k range.
Sometimes the dash lights die and come back on after a bump in the road... so prolly a bad connection there. Wobbly tach and dash lights problems dont seem connected tho... but not sure.
Problem is the tach... i replaced a few (have 2 spare) but the same thing happens to all of them. Any ideas?

LP

[randy]

Strom, same thing with my tach, and it's (was) NOS 2 yrs ago, wobbled from day one.

[cywelchjr]

If your connections are good, and your field coil and stator are good, replace the regulator.

That was my question. The stator windings are slightly out of spec (1.1 ohm instead of the .8 ohm I believe) so does just so slightly out of spec mean bad or just old? The field coil is right on spec, but my XS400's stator windings are out by almost exactly the same amount and it's charging system is working wonderfully.

I'm almost at the end of an auction for a alleged good used reg/rect on fleabay right now, with less than 8 min to go. Unless someone else bids I look to get it for $10 which I figure should be worth it. I might go ahead and bid on a stator that's on there right now if the price is right, the only question I have is will a special stator work on a standard? Same year and all but the fleabay one is from a special and I have a standard.

[randy]

Yes, the special and standard stators will interchange.

[TopCatGr58]

Hey Cy,

I hope the eBay reg/rect works for you, but you have to remember that it's still 25 y/o parts, and the old electrical parts are/were not as good/strong as some more modern components, so it might last a season, or 3, or forever, but seriously doubt it!

So..."when" it fries, contact GEEZER and get his robust unit guaranteed for LIFE...his...not the unit , since he makes them himself using much stronger parts, provides a stronger charging current at lower rpms as well! See the Parts for sale STICKY thread for details!
T.C.

[cywelchjr]

Hey Cy,

I hope the eBay reg/rect works for you, but you have to remember that it's still 25 y/o parts, and the old electrical parts are/were not as good/strong as some more modern components, so it might last a season, or 3, or forever, but seriously doubt it!

So..."when" it fries, contact GEEZER and get his robust unit guaranteed for LIFE...his...not the unit , since he makes them himself using much stronger parts, provides a stronger charging current at lower rpms as well! See the Parts for sale STICKY thread for details!
T.C.

Thanks, I'm planning on it. Just need to economize on it right now just to get things right until I'm ready to do it right. For now I just can't justify 115 over 10.

[cywelchjr]

Good news is that the ebay rect/reg did the trick. Bad news is that I found my fuse box is history. I have installed inline fuse holders while I order and prep a new fuse block (got a source, just gotta order it and then wire it in).

I also found a bunch of wiring problems on the back half of the bike (vetter hardbag mounting system added and the wiring on the moved turn signals is garbage, so I'm going to be fixing up some wiring.

But, battery is now fully charged after a day of riding, and I didn't have to use the charger to get it there.

[tarzan]

You know TC sells a replacement fuseblock with blade fuses.I bought one earlier this year.It seems like it was under ten bucks.Dont quote me on that ,but it is inexpensive and works great .Even has a couple extra fuse stations.:So you might want to look at that.If interested just search in the tech tips.