520h not charging

[Horse Newbie 6,861]

On 4/21/2017 at 9:28 PM, cleat said:

If the voltage at the regulator is 13.6 and the battery is seeing less then yes, you have a break in the wire somewhere.

 

The 88 & 89 models ran the charge wire from the regulator straight down to the starter motor battery cable through an in line 30A fuse.

 

I have rewired all of mine that way. Gets the charge current out of the 9 pin connector.

 

 

@cleat  I have a 94 520H and I suspect it might not be charging.

How do you check at the regulator? ...

Edited November 26, 2020 by Horse Newbie

[lynnmor 6,795]

4 hours ago, Horse Newbie said:

@cleat  I have a 94 520H and I suspect it might not be charging.

How do you check at the regulator? ...

 

Page 8-5 in the Onan Service Manual.

[Horse Newbie 6,861]

6 hours ago, lynnmor said:

 

Page 8-5 in the Onan Service Manual.

@lynnmor  I believe you have figured out something here... Instead of just telling me what I need to do, you seem to be leaning more towards "Read the manual".

I was thinking yesterday that maybe I should check the manual first, then ask you guys, but then again you guys know secrets that the manual does not have.

And besides, then I get to post here what I am fixing on my horse.

I'll check page 8-5.

 

As always, thank you.

Tim

[lynnmor 6,795]

Give a man a fish and you feed him for a day; teach a man to fish and you feed him for a lifetime.

[Horse Newbie 6,861]

3 hours ago, lynnmor said:

Give a man a fish and you feed him for a day; teach a man to fish and you feed him for a lifetime.

Okay @lynnmor   I'm fishing but I may be casting in the wrong spot...lol

I went to the manual.

Here's the lowdown....HELPPPPPPP!!!!!!!!!!!!

1.Had new battery hooked to Battery Tender all night. Battery volts at battery post 12.9 volts

Based on manual on Table 1 I am going by the 

SPEC A 20 AMP system.

2. Since the battery voltage was good- went to step 2.

Hooked red test lead to B+ on rectifier and black test lead to ground on engine.

Got .18 dc volts at B+ on rectifier with the wire to battery disconnected/engine running...

If I do the same test with the wire to battery hooked up I got 12.42 dcv  but I'm thinking I need to use the reading I got with the wire to battery disconnected because if it's connected I'm just reading the battery voltage correct. 

So I'm going to use the .18 dcv reading and move on to the next step.

3. I examined all wires and connections over the past months as I was doing other electrical work on the tractor so I do believe I am good there.

4. I unplugged the AC wires from rectifier hooked test leads to them and read the AC volts from stator. I got about 40 AC volts although I could not check it  exactly like the manual says because it says 21VAC @1800 rpm's, and 41 VAC @ 3600 rpm and the only way for me to know rpm is my tach and it isn't working with the wires disconnected from the RR. However I did get 40 vac at about mid throttle so for now I'll say it was within range for the test.

Now since as mentioned above I only got .18 vdc at the B+terminal and I'm using the 40 vac. as within specs...Step 4 says replace RR.

Would you agree ?

Okay so if I replace the RR I'm thinking I still have a bad stator because:

According to step 5

I connected one lead from my ohmmeter to one of the wires from the stator and the other to ground. It showed no continuity which it should.

I connected one lead on my ohmmeter to each wire coming from the stator. I got .6 ohms which is above the specified. 0.06 to 0.10 ohms...correct ?

I guess this means my stator resistance is not within specs and the stator needs replaced...

sound like I did the test right ?

 

 

 

[gwest_ca-(File Mod) 10,500]

Do not run the engine with the battery disconnected. That can do serious damage to other components that are still connected.

 

The voltage regulator needs to see battery voltage before it can regulate the charge current from the stator. Another reason to have the battery connected.

 

Leave the lights on with engine not running till the battery voltage drops below the 12.42 dcv. Let it rest for a while. Check battery voltage. Start engine and see if the voltage increases and if it does you most likely do not have a problem.

 

Garry

[Horse Newbie 6,861]

3 hours ago, gwest_ca said:

Do not run the engine with the battery disconnected. That can do serious damage to other components that are still connected.

 

The voltage regulator needs to see battery voltage before it can regulate the charge current from the stator. Another reason to have the battery connected.

 

Leave the lights on with engine not running till the battery voltage drops below the 12.42 dcv. Let it rest for a while. Check battery voltage. Start engine and see if the voltage increases and if it does you most likely do not have a problem.

 

Garry

@gwest_ca   I'll admit I do not do electronics well...

I never disconnected battery cables.

I did disconnect the wire at B+ on the rectifier ( which I guess is the same thing) now that I think about it.

So the B+ terminal on the rectifier is getting power from the battery, or sending power ?

 

Was I supposed to do step 2 with the B+ wire still hooked up ? If that's the case then I must have been reading battery voltage at 12.42 dcv

Edited November 27, 2020 by Horse Newbie

[lynnmor 6,795]

Since you are getting about 40 VAC from the stator, it is working.  Your ohm reading may be in error.  Like Gary said, keep things connected to prevent damage.  You should be getting more than battery voltage with the engine running, if not replace the regulator.

[Horse Newbie 6,861]

1 hour ago, lynnmor said:

Since you are getting about 40 VAC from the stator, it is working.  Your ohm reading may be in error.  Like Gary said, keep things connected to prevent damage.  You should be getting more than battery voltage with the engine running, if not replace the regulator.

@lynnmor  Thanks a lot for the response...

I think I answered my own question from above...

I was watching videos on YouTube and Taryl Fixes all was doing an engine swap and he got to talking about a rectifier.

The B+ terminal sends power to the battery, hence it's called the charge wire.

I will order me a Regulator/Rectifier and get that installed.

And Lynnmor you are probably dead on about my ohm readings.

I have a Harbor Freight VOM and I think it's been bumped or dropped one too many times.

When I turned it off it was turning itself back on

After I get the new rectifier installed I will run the test procedure again and see if I have different results, this time with ALL wires connected, and a new VOM.

I hope I did not damage anything by running it for a few minutes to get a reading...

but hey I learned something new today.

 

Thanks, Tim 

 

 

[Horse Newbie 6,861]

Have any of you fellows found these rectifiers for an Onan P220 at a local auto parts store ?

Or am I probably gonna have to order it online ?

[6bg6ga 271]

32 minutes ago, Horse Newbie said:

Have any of you fellows found these rectifiers for an Onan P220 at a local auto parts store ?

Or am I probably gonna have to order it online ?

I ordered one from Ebay several years ago. Depending on who is selling them the price ranges from about $13-25.00 and they work just as good as the factory part. You will find the factory part is a lot more expensive.

[Horse Newbie 6,861]

7 hours ago, 6bg6ga said:

I ordered one from Ebay several years ago. Depending on who is selling them the price ranges from about $13-25.00 and they work just as good as the factory part. You will find the factory part is a lot more expensive.

@6bg6ga  Thanks for the response...I did see where someone here had done some research (bench testing) on them and said he found that the cheapo's off the net performed just like the expensive ones.

I was wondering if any of my local auto parts houses might have them...didn't necessarily want to wait on mail order.

Edited November 28, 2020 by Horse Newbie

[6bg6ga 271]

Auto parts stores aren't going to carry them.

[953 nut 51,736]

18 hours ago, Horse Newbie said:

I was wondering if any of my local auto parts houses might have them...didn't necessarily want to wait on mail order

You may be able to find them at a large RV dealership service department. Lots of motorhomes use Onan but the will charge an arm and a leg for parts. 

[onanparts.com 178]

About ten years ago we offered the cheap imported regulators as an alternative to the high quality Onan OEM regulators. 75% return rate on the imported ones. 0% return rate on the OEM Onan ones going back 20 years. ZERO. Zip, Nadda.

 

Many of the cheap regulators destroyed new or known good batteries. Several were reported to have ruined good stators. There is a big difference between the cheap imported regulators and the high quality OEM regulators. We get 4-5 inquiries per week asking if our regulators are OEM Onan or imported. They had tried the cheapies, had nothing but problems, and were looking for the real thing.

 

Initial testing of both will show comparable results/readings. Real world use is night and day long term.

 

Some folks get lucky and have no issues with the cheapies. Most are not lucky...

 

You get what you pay for......