Another onan question

jon f mn · Jan 21, 2021

I got the onan back in the skid loader a while back and it runs great. Starts at any temp right quick. Has way more power too. The problem is it doesn't charge. I have two wires coming out from behind the flywheel and the wiring diagram shows one hooked to each side of the regulator with the ignition wire to the middle. It doesn't identify which wire to which side and I can't find any markings on the wires. When I had them hooked to the regulator one started smoking. I unplugged that one and it quit smoking but no charging. Any ideas what to look for?

Steve@Advance · Jan 21, 2021

It doesn't matter which terminal, if you're sure the wires are from the charge coil.

The regulator is really a rectifier, you're putting AC in and it sends DC out to charge the battery.

It's a low amp charge, charges all the time just enough to keep the battery up.

Billy Shafer · Jan 21, 2021

What is the model and serial number of the Onan. I can look up the print.

John T · Jan 21, 2021

Billy is THE MAN on this subject but the under the flywheel AC charging systems Im familiar with only have the two AC output wires coming out that connect to a rectifier block and it doesn't matter which wire is to which AC INPUT side. Ive seen a bunch of those rectifier blocks go bad which are cheap simple n easy to replace which can often cure non charging.

John T

jon f mn · Jan 21, 2021

Don't have a serial number handy, but it's a P218. Can get the serial number tonight if necessary.

gab · Jan 21, 2021

I got one of those P218s on a Wheel Horse that's going to turn 2000 hrs. about the second time I mow lawn this summer. It's a good runner.

Billy Shafer · Jan 21, 2021

P218 is good for right now.
Manual 965-0762
Page 8-7 will show you the onan print.

The regulator center post is B+
The outside post are the AC post
AC
B+
AC

If you go to Smokstak onan manual section. You can down load it for free.

jon f mn · Jan 21, 2021

That's what my service manual shows as well. So it doesn't matter which side those wires hook to? And what would cause that rectifier to start burning? I'm sure it is wired correctly unless those two ac wires can be reversed.

Billy Shafer · Jan 21, 2021

Ok you have the manual. The AC section does not matter. Most likly you have a bad regulator. As John T said they had a high failure rate.

1-903-536-2816 if you want to talk.

Billy Shafer · Jan 21, 2021

It is possible for the charging stator to burn out. But the most common thing was the regulator.

jon f mn · Jan 21, 2021

Thank you! I'll check the wires again. I do have another rectifier to try as well. I'll let you know what I find.

jon f mn · Jan 21, 2021

Thanks, I'll try the other rectifier I have.

wore out · Jan 21, 2021

(quoted from post at 11:20:42 01/21/21) Thank you! I'll check the wires again. I do have another rectifier to try as well. I'll let you know what I find.

The case of the rectifier/regulator has to be well grounded.

They typically mount to engine shrouding sheet metal and on some engines (NOT sure about your Onan) that doesn't work well over time.

The "fix" is to run a new ground wire from one of the regulator mounting bolts to bolt on the engine itself.

I'm NOT sure if a bad ground will "kill" the rectifier/regulator or just make it not work "til it's grounded.

Another onan question

jon f mn

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Steve@Advance

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Billy Shafer

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John T

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jon f mn

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gab

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Billy Shafer

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jon f mn

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Billy Shafer

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Billy Shafer

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jon f mn

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jon f mn

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wore out

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