1914 discharging
 

Hey guys, I have an electrical issue I need some guidance on. I went to run the tractor for the first time this year and found that the battery was dead. I put the charger on the battery and after an hour or so, got the tractor to fire up. After a little warm up time, I started mowing. When I engaged the pto, the ammeter showed a discharge of the battery. I continued to mow for about 15 minutes and then shut off the pto, to get off the mower without cutting my toes off. When i got back on, the PTO would not engage and the ammeter was still showing a slight discharge. I drove it back in the garage and shut it down. I tried starting a little later and couldn't even get a click. So i am pretty sure that the battery is shot, but would this cause the PTO to not start up as well? I haven't had time to do any other investigation, but since the engine was running and the ammeter still showed a discharge, i am thinking that there is something more going on. I am going to get a new battery this weekend, but past that...how do i debug if I am still showing a discharge?
Thanks!

Just a little more information, the seat switch and reverse cut off switch are disabled and have been for many years so we can eliminate those issues.

What makes you think the battery is bad? Did you check to see if it was charging when it was running? Dead battery does NOT = bad battery.

I just made an assumption...but the battery is 5 years old and when i put the charger on it, the gauge on the charger shows that it is 100% charged but it wont even turn on the headlights. After about 15 minutes of charging the battery will at least make the solenoid click. The ammeter only shows a discharge when running. Even worse when the PTO was running.

You either have a bad battery, or V/R, or BOTH.

Get the battery checked out.

Thanks Roland. If I have time today i will get a load test on the battery. They are on sale for 20 bucks at fleet farm so I wont be out much if i have to get a new one. Is there a test procedure for the VR?

YUP...the two Stators wires should have around ~30VAC and the output to the Battery should be ~13.7VDC. This is for a Kohler engine but the principle is the same......... http://www.onlycubcadets.net/forum/showthread.php?t=368

BTW...as a suggestion, if the battery is bad, I would buy the biggest CCA rated battery that will fit into your battery box.

Put a volt meter on the battery when it's running. At idle it should be at or around 13V. At WOT over 14V. If not, check output at the v-reg. This test is for a Kohler, but it is relatively the same for the Onan. Components vary somewhat.

Edit: Sorry Roland, go ahead. I'm waiting on parts and bored..... :beerchug:

Thanks for the info. I will try to get this tested over the holiday weekend. I will see what i can find for battery amperages. I think the one that is in there is a 250 amp battery.

Forgive my ignorance, but do the wires coming off the stator go directly into the V/R? If not, where do i find them?

YUP...:ThumbsUp:

Ok. I will get on it and get back soon!
Thanks for the super fast replies!

So I got some unexpected time to work on this so I got a new battery and found that the VR is at 13.3 volts. However the stator is showing 0 ohms. Now this is with a cheap digital multimeter but i think it might be right considering the regulator is OK. I know nothing about stators. What do I do now? Just a question, if the stator is truly bad wouldn't the engine die if the battery was dead?

Is it at 13.3V when running? Idle or WOT? If so, then you have to be testing wrong. The stator can't be open and still charging.

I Just tested again but this time I had a helper. At wot I only have 12.5 Volts. I checked 3 times so I am pretty confident this time. No idea how I got the earlier measurement.

So...... are you asking what to do next? :bigthink:

Yeah. Pretty much. I assume that the stator is bad. Is this something I can fix or is it a new part that is needed? Is this something I should bring to a shop? I can take most anything apart and put it back together but in this case I don't even know where the stator is located. Any idea of how much work the fix would be?

IF you are getting 12.5VDC, that isn't that far off. I am going to say I do NOT think it is a Stator issue.

FOR A TEST.....

Run a long jumper wire from the Battery Negative Terminal to the V/R Case (or housing) and see what you get when you measure the voltage.

So here is maybe a dumb question but I just noticed that the bolt holding the vr is missing. On top of that the po wrapped the vr in electrical tape so there is no ground to the vr at all. Could this be the problem?

The V/R HAS TO be grounded

Could it be that simple??? I will see what I can work out for a ground. It looks like the mount hole is oval from wear and the bolt is totally missing. Will have to get a little creative. I have to give credit to the p/o....the way the vr was wrapped and sitting on the motor looked almost factory supplied. Too bad it was wrong.
Will post my findings when I get it grounded properly

the Stator test is done with your meter set to AC volts with the engiine WOT.

but with the engine off, check if either stator lead has continuity to ground. that happened to me and I needed to replace the stator.

goodluck

On second thought - you would probably be blowing the fuse if your stator was shorted to ground. It could be open though.

Did you do the AC Voltage test on the stator wires? place meter leads on the 2 stator wires while WOT.

If its the same 3 prong VR that kohlers use it should have 2 bolts I think. 1 on each side. Are both bolts missing?

I had a 982 that the regulator attaching bolts were tight to the tin shield but the bolts that held the tin shield in place were loose causing a bad ground. Found it after I tried a different regulator. Tightened the bolts on the tin shield and cured the problem.

Yeah the bolt is missing. The po had it attached with a zip tie and wrapped with electrical tape so there was no chance of a ground. The bolt hole is completely worn and the threads are only present on one side. The bolt is missing from the shroud so I have to drill and tap a new hole or figure out a good ground in an alternate location. Hope to have more time tomorrow to work on it and I will report back. Thanks for the tip on AC voltage didn't even think of that.

And, which fuse would that be? :bigthink:

Just move it over a little and remount.

As far as the the tip on the AC voltage, the test we (Roland and I) referred you to said that..... didn't you read it?

Let me say, that I am not familiar with the Onan V/R setup. In the Kohler's V/R mounting, the V/R is located in the Fan Shroud to provide cooling for the V/R. When mounting your V/R this maybe a factor to consider.

That was posted on reply #7.

The blown one :beerchug:

The stator isn't fused there buddy....

Thanks chief, So there is no fuse anywhere on the B+ circuit? Would a shorted stator blow that fuse? I've never seen an Onan setup

Pulling the V/R up from the Parts Manual, this is what it looks like.

It definitely needs to be grounded and cooled.

There is NO FUSE in the Stator output to the V/R circuit.

There is a 12V (10A or 15A depending on chassis serial number) Fuse in the battery feed to the electrical system.

Which would not blow if the stator dead shorted. Only affects the B+ circuit. From the vreg/rectifier, this fuse is not affected.

See above.

No, my point is a shorted stator would not blow a fuse. No matter what engine it is on.

Are you sure?

My experience was different on my M20 last year. Bad stator blew B+ fuses over and over. replaced stator and all fixed and I tried everything before digging in that far.

I don't know why your tractor was blowing the fuse. Perhaps the regulator was also bad? Did you replace it too? Because, see, there are diodes in the rectifier that prevent voltage from going to the stator. The stator makes AC voltage, no 12V power even goes to it. It's an alternator. Only way that the B+ fuse would blow is if the v-reg/rectifier was pushing AC current into the system, or if it was bad and letting DC current into the stator. That's just how the system works.

Not to hijack this guys thread, hopefully he just needs to ground his VR.

Yes I did swap the VR on the M20.

If the stator is shorted to ground what happens when those windings start cranking out AC?