Charging Problems on MF135

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Birdhunter,

Sorry; volts. At slow idle; it was putting out about 12.3 if I remember right. At full throtle; it was putting out about 13.8.

All connections are clean except for the ones on the tractors meter. Those are the ones that I mentioned would be done later.

With the tractor off; I got 13 volts at the alternators battery lead and got 13 volts at the battery. When I turned the lights on; the battery would go to 12.8 - 12.7 (did not try with tractor running).

With the tractor running; I took a piece of wire and stripped both ends to see if I got a different reading by bypassing the tractors meter (touching wire on both poles of meter). No arching and no change in test meters reading. The connections on the meter look pretty bad so I am not sure if I made good enough connection with the stripped wire to warrant any change in the test meters readings. Hopefully when the two poles on the tractors meter are cleaned; it will make a little difference.

Thanks for your help.

Newton

 

[dqdave1]

Everything you mentioned says the charging system is working properly; ie: 13.8 volts at above idle; thats what it is suposed to be at; remember to high of volts and batteries hate you along with bulbs; If tractor is not running and you had 12. 7 volts battery is fine. Clean the terminals on ampere meter and see if that helps. Also you might want to turn off all electrical items on tractor and disconnect the positive battery post. Then touch cable slightly to battery post. It should not spark as you have NO load on battery (everything is off) If it sparks you have something that is drawing current and killing the battery. You will have to trace down problem by elimination. Switches sometime go bad and leave current on. Also you could have a positive wire that is shorting out on a metal ground. Start at battery and check ALL wiring. You will find it.

 

[Birdhunter1]

Are you checking voltage wit a handheld meter at the alternator or are you depending on the meter with the bad connections?

Also an ammeter won't help you much on your charging system now, swap it out for a volt meter mounted in it's place.

 

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Birdhunter,

Yes; I was using a handheld digital meter when I checked everything mentioned. Didn't even think about the meter on the tractor.

thanks
Newton

 

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dgdave,

Disconnected / connected battery several times that day and no sparks. I think that my FIL's tractor is fine now (other than being in rough shape / looks). The alternator when tested was only putting out about 10 volts and my FIL has decided to disconnect the battery after every use.

thanks
Newton

 

[dqdave1]

I agree with birdhunter1; change out ampmeter to a voltmeter. You will kow exactly what the charging system is doing.

 

[BigBoyinMS]

Just for info... I decided to do some work on my 135 over the cooler months and my first project was to rewire it. And since it wasn't charging I also decided to get rid of that externally regulated Delco alternator and replace it with an internally regulated Delco. The alternator swap cost me roughly $30. I picked up the alternator at O'Reillys Auto for about $22.00 and the extra pieces to wire it correctly were about $6.00 or so. Most will say you can just run 1 wire but that's not the best way to do it. Actually, it takes 3 wires to do it right and it's almost as easy. I'll include a link to a page I put up if anyone wants to do this. You can actually put it on almost anything that uses an alternator.
FYI, the least expensive alternator from O'Reillys was listed for a '70 Chevy Nova 350 even though the same 63 amp was more money if they look it up for other year vehicles. Only difference was the way the case is rotated and all it takes to correct that is to loosen the 4 case screws and turn it.
"Wiring the Alternator" Link

 

[dqdave1]

Why not just use the one wire method; tryed and true; proven on numerous vehicles as GM only used to use one wire. Three work but it adds extra chances of problems. Miswiring would be one; diode failure for two; extra cost for three; new alternator if improperly connected for four. Cannot see why you would not just run the one wire. I believe in KISS. The alternator is there to charge the battery and supply voltage to accessaries. Regulator is there to maintain proper voltage. Therefore the alternator you installed creates voltage which is sent to the regulator which sends it back to the battery via the one wire.

 

[BigBoyinMS]

Personally I like the KISS method too but there are two reasons that I decided against the 1-wire.
The first is that it isn't actually regulated because it has no way to sense the load. It charges at one rate so it's either over or undercharging.
The second reason is that it always has a small discharge.
Even if the diode fails or anything on the #1 connection fails then it still charges as a 1-wire.
Anyway, the option is there... feel free not to use it.

 

[dqdave1]

I read your listing for wiring with 3 wires; it concerns me as to why alternator has a slight discharge when you use one wire; I have never noticed a discharge. ( I will test with a meter when I get some time; it must be very low) . Also one wire systems usually do not use an amp guage; they use a volt guage which varies via the internal regulator as per BATTERY needs ( 13 or 14 volts) If your regulator is undercharging or overcharging the regulator is malfunctioning.