NOOOOOOOO a constant 30 amps is NOT normal (but subject to load). Maybe for a short time, but some of those old gennys (no idea what is on your tractor, many got changed over the years) weren?t much over 20 amps rated if that much, and 30 is about the max I usually saw on old Deeres (may have been after market too). Constant max or over rated charging current can over heat the generator. It may have an internal short? Orrrrrrrrr it may be okay once battery (if good battery) is better charged. NOTE with lights on they might charge more ya know.
The rate of charge depends (among other things) upon the battery and its condition and state and how good the genny and VR are functioning. Id expect high charge amps for some time but then it would back off as the battery level rises. If it stays at high charge rate CONSTANTLY despite a full charged battery, here are some (certainly NOT all) things that could cause the problem.
1) The battery is bad and/or has a short causing it to constantly draw high charging amps. A battery shop often for free can check specific gravity of each cell, measure voltage and perform a load test. Could be a bad battery or it or its wiring has a short.
2) The Voltage Regulator is at fault. If its field current control relay had its contacts stuck it can cause high charge out of the Generator. Or the VR may not be wired correct. Is the VR correct to match the tractors polarity??? Tractor was original POS ground
3) There could be a short in the Generator having the Fields output termination (insulated FLD post on genny) constantly shorted where they terminate at the FLD post which would make the genny high charge constantly IE no regulation. There could be a short where they pass out thru the insulated FLD post bushing, perhaps the nut got over tightened and what should have been the insulated field connection got shorted to case !! See what happens if you remove the wire from the gennys FLD post (or FLD on the VR). If it still charges high max the field must be shorted ( perhaps on its output where it?s supposed to go to VR for a ground or elsewhere).
4) There may be a short somewhere either inside the VR orrrrrrrrrrrr the wiring from the VR to the Genny orrrrrrrrrrrrr inside the genny causing full field current constantly which causes max high charge out of the genny.
5) There may be a short in the wiring between the VR and up to the ammeter then to the battery which is drawing current causing the charging system to keep trying to supply current to fill the need.
6) The VR isn't wired correctly !!!!!!!!!!!!! FLD on VR to gennys FLD post..........ARM on VR to Gennys ARM post.........BAT on VR up to ammeter/battery.
7) Is it a 3 terminal BAT ARM FLD or a 4 terminal BAT LOAD FLD ARM Voltage Regulator and is it wired correct?????
What's supposed to happen is the VR senses battery state and voltage then as more charge is needed the field is supplied a better quality/time/modulated ground via the VR's filed current control relay BUT if the gennys Field output is dead shorted that causes max continuous UNREGULATED current.
Similar to what teddy was talking about removing the wire from FLD on genny to FLD on the VR can help find the problem. If she continues to full charge (and it is NOT a battery or short problem) the VR is out of the equation and I suspect a short of the fields output to ground causing constant high charge.
SUMMARY I would have the battery tested (specific gravity and voltage and load test). If it checks okay, try to give the battery a full deep charge with a charger then start her up n see if it still stays at 30 amp charge ?? Maybe if the battery ever gets full charged the charge rate will decrease GIVE IT A GOOD CHARGE THEN SOME TIME TO SEE IF IT STABILIZES.............. See what happens if you remove the wire on the gennys FLD post (or VR's FLD terminal)............Insure VR is wired correct
I'm thinking a two brush genny here. If its a three brush many are adjustable to reduce charge rate.
Measure battery voltage and see if and how it changes with tractor running. If full charged at rest and stabilized it would be around 12.6 volts but under charge it should rise to at least 13 up to 14+ volts subject to RPM and battery state and charging system capacity.
If accidentally the Gennsy wasn?t? polarized correctly and the tractor was ran it can damage the VR !!!!!
Bad battery,,,,,,,,,,short in wiring,,,,,,,,,,,,shorted field in genny or at its external termination,,,,,,,,,,, bad VR,,,,,,,,,other causes ????
I'm sure I missed a few possible causes, so hopefully the other fine gents can add to this. Removing the FLD wire on genny will tell us more. Heck you may just have a battery or VR problem or perhaps once its full charged it will function correctly??
John T
