New MF593 charging/battery problem

Ranger510 · Jun 5, 2011

So my Father bought this tractor new last year, was a last years model (no computer) so it makes it a 2009 or there about.

The problem is that many times that I run it for two or more hours, the battery runs down to the point that if I turn it off, it will not start. Also if running the air conditioning, lights, and radio at the same time (night), it is such a drain that it will shut-off all of the electrical equipment.

We have replaced the alternator under warranty, other than that the dealer has been no help whatsoever.

I have checked voltage levels before but don't remember what they were, so if someone will tell me what to check, I'll be happy to post. (Charger is on it now)

I've also wondered if it could be a ground problem (new tractor/paint) as it doesn't happen every time.

Is there a separate voltage regulator that could be the culprit?

After being stranded on the "back 40" again today in 100+ heat index, I've had enough!

Thanks in advance....

JasonHall · Jun 5, 2011

Make sure the start aid is turning off after it is started. That is glow plugs or grid heater, which ever you have. I have seen this with other makes. The heater will pull more current than the alt can supply.

Ranger510 · Jun 5, 2011

Thanks, I do know that the indicator lights are out. How would I test to be sure the starter aid is turning off. That also sounds expensive once it burns out the glow plugs and/or controller from overuse!

JasonHall · Jun 5, 2011

A volt meter is your friend. Check voltage to the plugs/heater them selves. If there is no voltage there, they are not on.

To check for ground...take your volt meter and place the negative probe directly on the negative post of your battery. Take the positve lead and start checking different places... first the frame, second the engine block, and then the body of the alternator its self. All with the neg lead on the battery neg. post. You may need to make extensions for your leads. In all cases you should read less than a 1 volt. More than that shows high resistance in the ground side of the electrical system.

Ranger510 · Jun 5, 2011

Thanks, I'll start on that tomorrow. Really appreciate the help and I'll post if it solves/find the problem.

JasonHall · Jun 5, 2011

Another way to double check the ground, take a set of jumper cables and connect it to the neg of your battery and to the other end to the engine block. The body of the starter is great if you can get to it. If the problem goes away, you have a ground issue.

All in all however, if the voltage that you measure directly at the alternator is the same as what you measure at the battery, (with in about a 1/2 volt) it is likely not an issue with resistance in the charging system.