California
Super Star Member
- Joined
- Jan 22, 2004
- Messages
- 14,922
- Location
- An hour north of San Francisco
- Tractor
- Yanmar YM240 Yanmar YM186D
There's a thread on here somewhere about that 'dynamo'.
To summarize, early ones had rectifiers on the back but by the time of your YM2020 the rectifiers were external. Output of this dynamo is AC, so test for AC output, and also for continuity (a few ohms resistance) between its two wires to verify that the coils inside are intact.
That dynamo is universal. It is used by Yanmar, Kubota, and a lot of lawn-care equipment in the under 30hp category.
Nearly always its matching regulator is the problem. If your regulator has a 6-wire connector, then any regulator on Ebay that looks the same and has wires ending with the 6-wire connector - will be the same generic regulator.
This YM186 wiring diagram shows that its dynamo doesn't use chassis ground. I expect your 2020 is wired the same.
Does anyone have a link to the prior thread that discussed troubleshooting this dynamo/regulator combination?
To summarize, early ones had rectifiers on the back but by the time of your YM2020 the rectifiers were external. Output of this dynamo is AC, so test for AC output, and also for continuity (a few ohms resistance) between its two wires to verify that the coils inside are intact.
That dynamo is universal. It is used by Yanmar, Kubota, and a lot of lawn-care equipment in the under 30hp category.
Nearly always its matching regulator is the problem. If your regulator has a 6-wire connector, then any regulator on Ebay that looks the same and has wires ending with the 6-wire connector - will be the same generic regulator.
This YM186 wiring diagram shows that its dynamo doesn't use chassis ground. I expect your 2020 is wired the same.
Does anyone have a link to the prior thread that discussed troubleshooting this dynamo/regulator combination?