dalem

After trying everything possible, including replacing the wiring harness (used one) I replaced the regulator with a Kawasaki OEM part $131 not cheap but it's charging now. Those  cheap aftermarket regulators  are not compatible with Kawasaki's electrical system. I tried three and none of those worked. I have a 98 Honda 300 4 wheeler and I put an aftermarket regulator on it about  five years ago and it still works OK.  

What year is your mule 610 ?

I have stock lights. Nothing added on this Mule. I did see another post with a mule 610 charging problem and she I have the same problem but my 08 Mule 600 calls for a regulator P/N 21033-0010 (5 wire system ) hers a P/N 21066-0039  (4 wire system).  Doing a little research  this changed in 09 the charging system circuit  eliminates the brown wire does anybody know the reason for this. They both have the same  6 pin connector.

I'm having the same problem on a Mule 600 two regulators and still not charging. My stator checks ok. Where did you get your regulator? Was it an aftermarket or Kawasaki OEM part?

The new battery works ok.  I read the same battery voltage running or not. I checked all connections to the battery and grounds all are OK. If I use the lights the battery voltage will drop while its running. Two aftermarket voltage regulators and the original all do the same thing the battery voltage stays the same (now at 12.25 vdc) if I don't use the lights. I just keep recharging the battery(every other week). I use this mule everyday. I'm just wondering would a genuine Kawasaki Regulator make any difference (they are a lot more expensive)

The battery connections are perfect and should be on the positive at the solenoid but I'll check it to be sure.  I had changed the starter last year. Now I did not check the negative side to the frame, I will check it out tomorrow. Thanks! I see in your picture you have a 550, I have a 550 also, looks just like yours. They are good utvs also

Earlier this year my battery was weak and I had to boost my mule to start it then I decided to remove the battery to check the fluid level which was very low, I set the levels and recharged the battery a few months later it did the same thing, so I had to boost it again then checked the voltage running was getting around 16 vdc ( which is too high) and fluid level was very low again and wouldn't hold a charge. Note: The battery was maybe 1-1/2 years old. Then I replaced the battery and checked the voltage running nothing changed I was only reading battery voltage it wouldn't increase with increased engine speed. I changed the voltage regulator with an aftermarket  one, same thing not charging. I checked the alternator per the service manual which states .3 ohms or less it checks at .2 ohms and not shorted to ground. With the engine running I disconnected the alternator and it had around 22 vac idling and around 60 vac revving the engine, so I figured the regulator was bad so I replaced it with another new one (aftermarket) from a different company, again not charging only reading  battery voltage. I did put the original voltage regulator on nothing changed still not charging. Using the manual wiring diagram did continuity checks going to the voltage regulator everything checks out OK. Now what am I missing?