Overcharging, Frustration!

[WheelhorseBob 1,548]

I have a very low hour 520h. I’m doing a light restoration on it and the only known issue I have with it is overcharging. I replaced both battery cables with marine grade tinned cables. I replaced the voltage regulator with a cheap eBay version and have cleaned numerous connections. What gives? Still showing 16 on the gauge. BTW when I first started it after the new voltage regulator was installed it was charging at 13.5. When I increased rpm it went to 16. 

[Tractorhead 8,610]

Did the „cheap ebay regulator“ be able to last the max Charging current?

i doubt.

 

it sounds for me you used a too weak Regulator or it was wrong mounted or maybe a short on ac lines.

 

The regulator should be able to deal with on a load of 15A .

Check for a 15A regulator or better a 20A type than some spare will be available.

Mount it flat on a metal sheet surface to get some cooling

as long as it is not the original regulator what have it‘s own place.

 

check if of both AC lines are non scratched on insulation from coil to regulator

There sould be no ground contact between „Ac in“ terminals on regulator

check what you get on unloaded chargingcoil on AC Voltage

check if all connectors are tight and fit

check if there is a clean ground between Engine and chassis ( Frame)

 

 

[squonk 38,911]

Get a hand held voltmeter and double check. Those dash voltmeters are horribly inaccurate.

[WheelhorseBob 1,548]

Ok, I should point out that I've checked the voltage with my fluke meter. The gauge is accurate. The "cheap eBay regulator" is for this model Onan. It is a direct replacement and mounts in the same location. The ground to the chassis is clean and the ground cable is new. All connections on the regulator are clean and tight. I'm not sure where else to look for the problem.

[Tractorhead 8,610]

sounds you got a worse regulator.

 

Warranty?

 

AC voltage on AC Terminals should point about 28Vac at Full throttle (3600 RPM) without any load.

if it exceeds that much, maybe a stator is worse, but i‘m more on the Regulator side.

Edited August 31, 2020 by Tractorhead

[rmaynard 14,888]

I agree with @Tractorhead. Sounds like a bad regulator. I put an after-market regulator on my Onan and it works fine, but that's not to say that you may have gotten a bad one. I have been using Amazon for parts more than eBay lately. Amazon has a much better return policy.

[lynnmor 6,770]

The body of the regulator needs to be grounded to the engine tins.  That ground path needs to go back to the battery, so the tins need a good connection to the block and the block needs to have a good connection to the battery cable.  For a test, run a wire from the voltage regulator bolt directly to the battery negative terminal, if the voltage corrects it is a grounding problem, otherwise the regulator is toast.  I have used the cheap regulators without issue, probably luck of the draw.

[Tractorhead 8,610]

Great advice from lynnmore !

 

Buying a lot of cheap ebay parts just to play with different results, but most of mine experiences are positive.

sometimes long deliverytime, sometimes they here within 3 day‘s  by Airmail (faster than from some German dealers)

The „you get what you pay for“ is here not allway‘s given, it depends on the Dealer ( not on the responses)

Mostly i be surprised about real steal deals.

 

The original regulator for my old onan was also fried, than i ordered one from bay and it stops working after 2 hours.

i measured the AC input what shows me 27,8V

I wrote the dealer, what he thinks that could be happen, sent him some measurements made with picts 

and they resend me cost free exchange that worked - even 6 Weeks later after the first was arrived and he get my response.

A good dealer imho i purchased a lot electronics from him since.

 

So would try it to get exchange.

[WheelhorseBob 1,548]

I’m no electronics wiz buy a long shot. I used my meter to check resistance from the negative battery terminal to the regulator body and got a reading of 0.1. That means I’ve got a very good ground correct? So if I have a good ground can I test the regulator itself? If so how?

[lynnmor 6,770]

If you have 20 some VAC at the outer terminals and put that jumper in place like I said on a previous post, you are checking the regulator.  The resistance measured may vary with the engine running and with voltage applied.

[Tuneup 1,416]

I bought a Harbor Freight compression tester and it had me thinking my old Honda needed a rebuild. Heck, was fine! Just wanted to check it. Read about 50% low. Chinese garbage. Luck of the draw is absolutely true. You have a Fluke DMM so you appreciate the finer things . Time for another regulator.