Charging Problems on MF135

fig · Nov 1, 2005

Guys,

Need some guidence. My FIL has a MF135 (gas) that he says is not charging. I will go down to his farm with him Saturday to try to help him diagnose. It sounds like the voltage regulator to me, but this is what he is telling me:

meter shows discharge until RPM's are up pretty high and even then it only just comes off the mark. He thought it was the battery so he has already replaced it with a new one, but he went down the other day and it would not turn over (discharging while running not sitting).

What would be the best way to diagnose with a volt meter? What should the alternator be putting out?
Can you check voltage going into and out of the regulator to see if it is in fact the problem?

I forgot to mention; I hate electrical problems!

Newton

Birdhunter1 · Nov 2, 2005

( What should the alternator be putting out?
Can you check voltage going into and out of the regulator to see if it is in fact the problem?)

ARe you sure it has an alternator? Those tractors came out with genertors, some of the later ones may have had alternators but the early ones had generators. If it has an alternator you should get like 13.8 or 14 volts out of the alternator, if you are gettign this and the batteryis still not charging check your voltage regulator.

If it has a generator and it is not charging the battery then take it off, throw it away and get and alternator, you will be much happier having done this!

kensfarm · Nov 2, 2005

"meter shows discharge until RPM's are up pretty high and even then it only just comes off the mark. "

My MF65 acts the same way.. clean off the electrical connections and battery terminals and the amp meter will jump up a little higher. It still requires the higher RPM's to show charging.

fig · Nov 2, 2005

Birdhunter and kensfarm,

Thanks for the responces.
kensfarm: I will make sure that all connections are clean and tight to start with when I get down there.

birdhunter: I am not sure if it is a generator / alternator. My FIL says alternator, but he could be mistaken. If it is a generator; would it still put out 13 - 14 volts? If it is a generator and it is bad; do you know what kind of alternator to ask for at the parts store?

Newton

Birdhunter1 · Nov 3, 2005

As far as what the output shoudl be I don't know since I never checked ours when it worked and when it didn't of course the output wasn't right.
You could just simply need to field the generator. I don't remember how to do it exatly but I did that to ours after changing a regulator and it worked great, till it shot craps.

If you want to go the alternator route I'll look and see what the number is off of mine, it is an AC/Delco part# and it has a self excitign regulator in it, meaning it has to excite itslef since the RPMs may not ever get high enough to ever excite the regulator. All you need to do for that is run a wire from the battery to a post on the side.

Almost any older parts store that has a tried and true techie in it could help fabricate something up for ya, or an battery/alternator shop.

rcraft · Nov 3, 2005

When checking the output of the charging system, place the volt meter on the battery terminals. In order to charge a typical storage battery in cars or tractors the charging system needs to put out 13.5 to 14 volts whether it is a generator or alternator. Alternators are more efficient at lower engine RPMs.

fig · Nov 4, 2005

Thanks guys.

Birdhunter: I would be interested to know what the part / model number is on yours just in case I need to go this route.

Newton

Birdhunter1 · Nov 4, 2005

Just let me know if you need it.
I know it has an internal regulator, so the wiring will be very simple after you change it out!

fig · Nov 7, 2005

Birdhunter,

Thanks, but I went down this past weekend and it did have an alternator. The previous owner had already changed out. The wiring is a mess though.

Even though the voltage regulator was working (opening and closing); we took it and the alternator off and took them to Advance Auto in town (about 30 miles away). The alternator was only putting out about 10 amps. We replaced it and the voltage regulator, but it still only puts out 13.8 amps at full throtle. The connections on the back of the amp meter look pretty bad, so I will go back one weekend with the FIL to disassemble / cleanup and reinstall. Maybe this will improve the output.

Thanks for the help.

Newton

Birdhunter1 · Nov 8, 2005

( Birdhunter,

. The alternator was only putting out about 10 amps. We replaced it and the voltage regulator, but it still only puts out 13.8 amps at full throtle. The connections on the back of the amp meter look pretty bad, so I will go back one weekend with the FIL to disassemble / cleanup and reinstall. Maybe this will improve the output.

Thanks for the help.

Newton )

13.8 AMPS or do you mean VOLTS?
13.8 Volts is good, it could help the charge to teh battery if the terminals wre clean but you shoudl be OK. What happens when you turn the lights on, are they REALLY bright or kinda dim and getting dimmer?