Another Charging problem

[Steverk]

I have a charging problem that is driving me nuts. Like other threads I've read, I am not able to solve a problem with my charging system. Below I'll describe my diagnostics so far. Note: this is a custom build so I have relocated all electrical components to under the seat and I am using the original wiring harness.

Last summer; I started the bike for the first time after a complete rebuild. At that time everything worked perfect. 14V to battery, tach worked, headlight etc.

Last month; started the bike it runs great but no tach, no charge to the battery. I performed diagnostics as described in the Clymer manual that I have. Field coil @ 3.8ohm, stator @ .6, .6, .6ohms-- a little high so I replaced with a spare that tests in spec. I start the bike, no change even when revving. Checked all the grounds and they are good. double checked and cleaned all connectors, twice.

Thinking it was the VR, I bought a used OEM VR off of eBay-- no difference.

Taking a chance I now bought a new aftermarket VR off eBay and installed it-- no change.

Next, I installed another Stator and Field coil assembly from a spare engine (both tested in spec)- no change. So i then installed the previous 2 used OEM VRs- no change.

Each time I tried a new combo or part, I tested the alternator case for signs of magnetism-- each time nothing. Also, each time I have tested the stator output via the white wires- no voltage (tested in AC mode on my tester).

I am quite confident that I do not have a ground or connector problem as I have tested continuity and resistance across both connectors an things are good there. I also tested the VRs red and black and read 12V with the key on (someone confirm this is a valid measurement).
The best I can determine is that none of the VRs I tried are not energizing the Field Coil-- but why?

I also only have a 2 wire (green and black) connector to the field coil, and no brown wire that others have referred to.

Any experienced help would be appreciated
Steve.

[DEEBS11]

The used regulator is, of course, suspect. The new regulator- what brand? Ricks? Geezer/Oregon? Chinese? If Chinese (around the $30.00 price range) you must purchase a quality regulator (usually over $120.00 range) to continue your testing.

[DEEBS11]

A few easy areas to check that can cause problems.

[DEEBS11]

More info:

[LAB3]

Deebs, take a look at the wiring harness schematic and see if you see what I see. The field coil uses a positive lead from the harness (brown wire) and grounds itself through the green wire going to the R/R, I'm pretty sure what we're seeing here is is simple wiring mistake, the field isn't being excited. If that's the case there's no way the alternator can make power

[DEEBS11]

I agree that there is, more than likely, an error in wiring. Could be a component such as the regulator. Too many variables at this time. However, if you look at this diagram you can see the green wire gets its signal from the field coil. When the magnet rotates past the field it generates current which is the green wire input on the regulator. I suspect this is some sort of "enable" or "excite" portion of the regulator which only turns the unit on if it senses the motor spinning (Geezer could explain that better than me). I think the brown wire just powers the unit. The red wire is regulated output and is keeping the battery charged. The unit is grounded through the black wire (two actually).

I work on a lot of late 70's early 80's Kawasaki's and they only have the three phase AC inputs (usually yellow), no field coil, and a ground and a 12v output (sometimes a brown wire that monitors the system voltage which might do the same thing as the field coil without all the hardware). You can measure AC on any of the three AC legs with the engine running to see if your regulator is bad. A simpler design.

[DEEBS11]

So, I read some more. When running, the field coil generates a small voltage (about 1.7 Volts DC). This is between the green and black wire. Again, some sort of small "enable" signal when the engine spins.

The only stator test is basically continuity. All three white legs should show continuity but must not be grounded. Same with the field coil - continuity but not grounded. No AC voltage checks. Very interesting but it makes it harder to diagnose with a volt meter.

Don't worry about magnetism of the rotor, that is reliable as a hammer. Never seen one fail on a bike unless visually cracked.

[DEEBS11]

This is a possible explanation why the tac does not work but it could also be a wire issue. Lots of testing to do. Should be able to find it.

[Radioguylogs]

I haven't done any reading like Deebs, but I am thinking it works like Lab3 described.

I expect the purpose of the field coil is to generate the magetism to generate electricity.

I vaguely remember some old posts that mentioned sticking a feeler gauge to the rotor mounting bolts to confirm the magnetic field is present.

I am thinking the brown wire is missing and the black wire was substitued even though it is supposed to go to ground.

[DEEBS11]

That's interesting. The green wire goes to ground to turn on the coil which turns magnetic. Does that mean the rotor does not actually have a magnet in it like a Kawasaki does?

[LAB3]

The XS11 uses an electromagnet much the same way a car alternator does. Can't say I know FOR SURE how the Kaw works but every other bike I've owned uses permanent magnets. In a system such as the XS11 the power of the magnetic field is varied depending on how much energy the system requires, it's output is dynamic. In a permanent magnet alternator you're always making the same amount of power, RPM dependent of course. The R/R in that case must dump that unused power somewhere. The XS11 charging system IS more complex and I'm assuming costs more to build not to mention taking up more precious space on the bike BUT is far more robust and runs cooler since it only makes the power it needs negating the need to dump the unused energy back out of the system

The XS11 tach rather curiously counts it's revs off the output of the stator windings, it makes sense that if if the electromagnets are not creating a magnetic field then there are no pulses to count.

I'm not sure if there's another two pin connector with a green/black combo anywhere on the wiring harness and at the moment am not in the position to look into it but my best bet is that this is just a simple "Something got plugged in wrong" situation.

[Steverk]

Gents, thanks for the feedback

i don’t have tach, headlight, or gauge light because there is no alternator output. DEEBS11 thank you for the diagrams and these are similar to the Clymers manual. You also in the right lane regarding the two OEM VRs as they both could be bad. The new eBay one I bought is a Chinese unit, but I bought I thinking I could use it temporarily to validate the others were bad. As far as wiring goes the harness is stock and I have not altered it in any way for this circuit.

the field coil tests within spec, and there are no shorts.

I guess I will need to bite the bullet and buy a high dollar unit

[Ranger_xs1100]

That's correct Deebs, No magnets .

[Ranger_xs1100]

By the way, I had a bad rotor on an xs650 which resulted in not charging. I think was a fairly common failure on the 650s. I believe they used inadequate windings. But I haven't seen an xs1100 rotor go bad.

[bikerphil]

A quick test you could try is to tap into the green field coil wire and touch it to ground with the bike running and see if there is charging voltage. If so, then the regulator is most likely at fault. Don't leave it grounded for very long, only for testing purposes.