S650G voltage regulator issue

[KonigJager]

Hi, new to the forum and tractor ownership. Picked up a Satoh S650G a few weeks ago and have been working on getting it back into good running shape. Current issue I am fiddling with is the charging system. With the old mechanical regulator it puts out over 16 volts. Not wanting to cook my new battery I bought a new voltage regulator (IM-952). Went to install it yesterday and also replaced the terminals and connector housing for the alternator end since it was crumbling.

With the new regulator it won't charge at all and the charge light comes on and stays on. Swapped the old regulator back in and the charge light goes out once the engine is running but still puts out over 16 volts.

I have checked the wiring between the alternator and the voltage regulator and it checks out with 0 or very slightly above 0 ohms. Checked the battery ground and battery positive as well and found no issues.

Took the alternator over to Autozone and while the bearings sound like they are starting to go out the guy was able to get it to charge at 14 volts no problem.

From my research it appears that technically the replacement regulator should actually be the IM-951, though when I talked to the shop I bought the IM-952 from they said the only difference they could really see was the IM-951 has an extra bullet connector coming off the connector and either should really work.

I'm pretty good at a lot of this stuff but dealing with old style charging systems is not my strong point yet. What else could be causing the issues? I opened up and cleaned the old regulator already as well.

 

[Bayfisher]

charge the battery fully and measure the standing voltage at the battery, start up the engine with the test meter connected and monitor the voltage, should start
high then drop to around 14v, this should happen quicker when @ 1000 rpm, u may need a new battery.

 

[KonigJager]

It has a brand new battery. Hence trying to fix this so that it doesn't roast it and waste the $140 it cost me for the size I had to get. Drives me nuts that odd sizes, even if much smaller than other sizes, can end up costing twice as much as more standard sizes.

 

[Sonny580]

Mine quit charging 10 years ago. I just charge it up and go for the day! --Ya, NOT handy but works --- old battery been on it for 8 years too.
You say you had your reg. top off? You can adjust the points in there to set higher or lower rate and kick in/out level on the old regs. -- they usually have jack screws under the stiff arm that you run up or down to set them. IF they dont I used to just bend them a bit---kinda tricky but will work for a while til you can get new reg that works. They probably sold you a dud and as for your new battery ----It can also be a dud! --- new aint always good!

 

[KonigJager]

Took another look again today during lunch. Terminal A on the alternator was pretty corroded so I took a small file to it and cleaned it up as best I could. Also blew out all the crud from inside the alternator. Double checked the wiring and put it all back together. Now it works with the new regulator and charges at 14.3 volts. So it was likely that terminal on the alternator causing the problem. A bit surprising given the mechanical regulator would at least mostly work, but maybe that is why it was overcharging to begin with. At any rate it's up and running again and I am just going to go with the new electronic regulator.

Still have a ton of other little things to fix up on it. I am going to start another thread to document most of what I do on this thing. I have a huge thread on my Hummer H3 on another forum and find it's useful in a few ways. One I can look back at my posts to see what the heck I even did on something and two others can see what can be done and how to do it.

Thanks for the responses y'all, I appreciate it.