Charging issue

[WheelHorse520H 708]

Hi everyone,

I have a 1988 520-H and it seems to take a long time to charge the battery. Is this normal? It is right around 12volts but when running the voltmeter on the dash does not go much above 11.75v - 12v.

Thank you all for the help,

Andrew

[lynnmor 7,815]

 

Download the Onan Service Manual here.

 

Start troubleshooting on page 8-3.

 

If your voltmeter is correct, it is not charging.  After you tried the steps in the manual and you still need help, please return.

[WheelHorse520H 708]

Thank you for the help I will look at this soon, I still have some other issues to sort out with this machine.

[Tuneup 1,452]

Hi Andrew!

Just a note from an old HP tech (the Bill and Dave HP, not the garbage of today), don't trust a gauge unless it's been verified. I wouldn't trust any dash gauge until I had a nice cheap DMM to verify it. The nature of derivation of a DCV in these handhelds makes the cheapest Harbor Freight DMM an accurate and worthy resource.

 

Oh - my 516H voltage gauge reads off the scale high when running but it's around 14 volts on the DMM.

Edited April 24, 2021 by Tuneup

[953 nut 59,924]

As @Tuneup said, you need to verify the reading on the volt meter. The voltage coming from the voltage regulator will increase as engine RPMs increase, are you running at low RPMs? Remove the connector from the voltage regulator and clean the terminals, a small amount of corrosion at the terminals can result in a large voltage drop.

[WheelHorse520H 708]

14 minutes ago, 953 nut said:

As @Tuneup said, you need to verify the reading on the volt meter. The voltage coming from the voltage regulator will increase as engine RPMs increase, are you running at low RPMs? Remove the connector from the voltage regulator and clean the terminals, a small amount of corrosion at the terminals can result in a large voltage drop.

I was running at operate so around like 2600 rpms I think, not sure tach stays at 2000 all the time unless I shut it off and then turn the key to run, then it lowers back to 0. I will look at them now, I am doing a lot on this thing today. Thanks for the help. I will return with an update.

[Tuneup 1,452]

Yeah, long day of rain today and I had the wifey help move the 520H into the garage so tinkering all day. To get the wife to sit on the puller 516 and actually move us along was yesterday's and maybe this year's greatest accomplishment. I'd like to get this 520 at least running today. We'll see.

[WheelHorse520H 708]

Hi, sorry I have been busy, @lynnmor the manual you sent me was a little confusing because I am not all that familiar with the voltage regulator. I tried testing the voltage of the battery while it was running but my DMM is weird it was not connected to anything yet and it was reading 0.1 - 0.5 volts, the number got higher the more the wind blew. And yes it was on the 20dcv setting. However when I had the tractor running I was getting a reading of about 12.6 volts.

Thanks for the help,

Andrew

Btw I had to trickle charge the battery this afternoon. Once before I started yard work and then again during. I don’t think it’s the battery though because I bought it only a little over a year ago.

Edited April 26, 2021 by WheelHorse520H
Forgot a part.

[lynnmor 7,815]

You test the stator by using a voltmeter on the AC setting and connecting to the two outboard connectors on the regulator..  You then check the DC output using the center connector and ground.  Use the chart on page 8-6.  Be sure that the regulator has a good ground at its mounting bolt.

A "trickle" charger will take days to fully charge the battery and depending on type and power it may never happen.  Keeping a battery in a low state of charge is the sure way of wasting it.

[pfrederi 18,666]

Load test the battery...How many electrical problems reported here went back to a bad battery  even if fairly new

[WheelHorse520H 708]

18 hours ago, lynnmor said:

 

A "trickle" charger will take days to fully charge the battery and depending on type and power it may never happen.  Keeping a battery in a low state of charge is the sure way of wasting it.

My apologies for not being clear, the battery was low enough that it would crank but not enough for it to start which is why it didn’t take so long.

Thank you for making more sense than the manual, I will test it tomorrow or Wednesday. The wires do not have to be connect to the regulator to test the stator correct?

16 hours ago, pfrederi said:

 

Load test the battery...How many electrical problems reported here went back to a bad battery  even if fairly new

 

I will do that later this week, before I got it running I did have to try and crank it over a bunch.

Thank you all for the excellent help.

Edited April 27, 2021 by WheelHorse520H

[WheelHorse520H 708]

So the stator was just above what the manual said, so that checked out but the regulator was a good couple of bolts below. This means I need a new regulator correct?

Thanks for the help,

Andrew

[lynnmor 7,815]

3 hours ago, WheelHorse520H said:

So the stator was just above what the manual said, so that checked out but the regulator was a good couple of bolts below. This means I need a new regulator correct?

Thanks for the help,

Andrew

 

Most likely, first check the connections on the regulator and the grounding at its mounting bolt.  I have had good luck with the cheap ones on eBay.

[WheelHorse520H 708]

1 minute ago, lynnmor said:

 

Most likely, first check the connections on the regulator and the grounding at its mounting bolt.  I have had good luck with the cheap ones on eBay.

Ok, I will clean them and see if it changes. Thank you again.

[WheelHorse520H 708]

On 4/28/2021 at 7:36 PM, lynnmor said:

first check the connections on the regulator and the grounding at its mounting bolt. 

I did this today, you don’t see how dirty something really is until you soak it in PB blaster and stub it with a wire brush for 5 minutes. It was still charging low, around 12.5 dcv going to the battery. I know a guy down the street, gonna see if he has a voltage regulator I could buy. I got it going for me today and was grading my dirt driveway when it stuttered, then stalled, and then backfired! Any idea what this is? I was thinking the weak voltage reg. was not charging the battery enough for it to have good spark. Also I considered too much of a load for the grading but I was pushing on flat ground, and have pushed just as much dirt uphill.

Thanks for the help,

Andrew

[Tuneup 1,452]

Yeah, a regulator is going to provide almost 14 volts above idle. If less and a good ground, time to replace. As for the load issue, with a weak battery all bets are off.

[lynnmor 7,815]

Check the 9-pin engine connector, it's the white plastic connector near the battery.  They often burn, especially at the red wire.

 

The electrical system doesn't care how hard you are working the tractor, it will perform the same with the possible exception of the trigger module and voltage regulator overheating and failing.

[WheelHorse520H 708]

I looked before to see if it was burned, but not before I got it running, I will check it this afternoon. Thanks for the idea, I know those are notorious for burning out.