Regulator help

   / Regulator help #1  


New member
Aug 9, 2023
This is a long story that I’ll try to keep short. I have a Yanmar FX 42 that has had repeated issues with charging. One of the previous owners or maybe all of them have done some wire repairs. And not the best repairs.

With this last charging issue I wanted to replace the regulator and the dyno. When I look up the regulator on Hoye is shows a 5 terminal setup. The regulator on the tractor is 6 wires with a connector. See attached photo one off the tractor in lower left. One from Hoye top. One I ordered from eBay bottom right. IMG_3591.jpeg

Looking at the wiring diagram for the tractor it clearly shows 6 wires on the regulator. But now my problem is what color wire goes to what? As you can see from the photo the one off the tractor and the one from eBay have the wire colors in a different order.

From some of my digging around and looking at other Yanmar wiring diagrams it seems the black goes to ground and the two blue go to the dyno. But I have no idea what the other three go to.

Can anyone help with this issue.

Thanks in advance. Sorry for the long post.

Attached wire diagram highlighter colors are not right just all I had on hand to follow the wires. IMG_3592.jpeg
   / Regulator help #2  
I'm thinking that it is a regulator/rectifier. First it will rectify the AC power into DC, then control the voltage.
   / Regulator help #3  
Does your old and new regulators have plugs on the end of the wire. Can't tell from picture, or does each one plug in separately?
   / Regulator help
  • Thread Starter
Yes the old and new regulations have connectors on them.
   / Regulator help #5  
If the plugs match I would plug it in and see what happens. If plugs match my guess they are wired the same, just different colored wires.
   / Regulator help
  • Thread Starter
I looked over my original post and see I forgot a key element as to why I need the wire colors and where they go. The connector on the tractor side when I pulled it apart fell apart and most of the wires came apart too. They are all the wrong colors looks like some scrap someone had laying around. So I have little to know idea as the what goes where. 😡

Wish I had taken a photo before I had pulled it apart. But I was not expecting this result.
   / Regulator help
  • Thread Starter
I will keep you posted on how it turns out. It will be a while as I am out of town for a few weeks.
   / Regulator help #10  
This looks to be wired the same. Same wire colors from what I can see. It's on a YM2000. The Org. old style Reg. is still there and works. VR. 550


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