Electrical Issues

[mikemc53]

Hi gang, need a little help here. I'm posting here instead of the specific UTV forum because the questions /problems I have are probably not specific to any particular model or brand and sorry for the length but wanted to give some background. For the record, my UTV is about 10/11 years old and it is a Trail Wagon 200, which I believe became American Landmaster. I've had it since it was new and I only use it in the summer/fall as I live out of state the rest of the year. It's lightly used for small projects around the property and to run out to the mailbox about 1/2 mile away. Winterize it every fall and remove the battery which is place on a battery minder. Never had any issues until late last year when the battery (I believe it was the second one) died and I bought a replacement. Well, the replacement died in less than a week so I figured I had some other issues. Checked everything and found no apparent shorts or bare wires so I returned the battery and bought a different make. Same thing, about a week and it was done. I hooked up my tractor battery to it and it was fine but it was not really a good fit so I tried one more time with a proper fit battery and it lasted the rest of last season and up until now everything was fine. About a week ago I was driving and it sputtered, one time, so I payed no attention and added some Sea Foam. A few days later it was running and started sputtering real bad - barely firing -  and it definitely seemed electrical. It sputtered for about a minute and would not move and then smoothed right out and ran fine. But, after I shut it off it was done. I checked the battery and it said it was around 11V so I figured I had better find this electrical problem. The battery charged right up to a bit over 13 but every time I tried the key...nothing and the battery showed low again. Pulled out one of my tractor batteries, which was fully charged and the same thing. No lights, no start but I do have power at my auxiliary accessory plug and when I disconnect my ignition switch (3 wire) I have power coming to it. I get no power across the terminals of my brake interlock, but I don't know if I am supposed to have it there. Something dumps the batteries down to around 11, though I do still get that 11V at the accessory plug and coming into the ignition. No lights at all and no sound from the solenoid or starter, though I thought that one time I heard a very faint click back there somewhere but only once.

Any help is appreciated. I am not sure how to check the regulator, solenoid or starter so suggestions are welcome.

Thanks

[kenfain]

This is a magneto engine isn't it? If so, then based on your description, that's where I'd start. 

[aefron88]

Sounds like you have a pretty large short.

I'm not familiar with that model so this will be real general:

I would hook a voltmeter to the batt and start removing fuses and replacing one at a time. That should help to track down the short circuit. When the vtage pops back to "disconnected batyery voltage" you have figured out which circuit the short is on. Once you figure out which circuit it's on you can go from there.

I would recommend using an ammeter in series, but if the draw is dragging the batt down to 11v instantly it's probably well in excess of the 10 amps most meters can handle.

Any chance the manual has an electrical diagram in it?

[Dale Stansbery]

I've been trouble shooting similar problems on my PU truck. I came across a method to test for parasitic current draw by measuring voltage drop across your fuses. You need a good digital voltmeter that can measure millivolts and a chart for your fuse type and amp rating.  When you get a voltage reading above 0, there's a current draw. then look up the voltage read on the chart for that specific fuse.  On a UTV I'd think the draw with the key off would be pretty minimal over all. For my truck, the suggested total parasitic draw to keep the computers running with the key off is something like 50 milliamps or less, a UTV is probably less. If you find a high draw, then you've isolated the problem circuit. The technique description and charts for the fuse types can be found here...  https://m.roadkillcustoms.com/how-to-perform-a-parasitic-draw-test/

Caveat, I just found this information, and haven't tested my truck. But, having an electrical engineering background, I find the theory solid.

[kenfain]

There's some good ideas here in this thread. But I think that everyone has missed the part about how it's dying WHILE  it's being driven.

That means that it's not putting out enough power to run itself.

A short that big, would easily drain the battery very quickly. It would be dead as a doornail after a couple hours, creating a no start situation. My idea is that you should check for power at the source. See if it's generating enough power to keep it running.

Check the voltage at the battery, while it's running.