Need in Depth Technical Help for my charging syste

First my system is a 3 brush, I believe not an internally grounded generator. It is a 300U. There is a 3 terminal, (actualyl 4 counting the terminal on the back of the regulator) regulator, and the light switch has a resistor in it. Now when I turn the light switch to the first position, the Headlights come on dim and the resistor on the switch gets hot. When in the seocnd position, the headlights opeerate normally.

Now besides that, when i start the tractor, the ammeter shows a charge of appx 20amps. The battery voltage has been anywhere from 7.5 to 8 volts. This bothered me, as I would imagine anything over 7.0 volts is harmful long term to the bttery. I tried adjusting the regulator, but I dont know what I'm doing, so I decided to get some imput before I touch it.

From my understanding the generator is either on or off, the regulator is just some relays and does not actually regulate the field current, it switches it on or off. Is peaks of 8volts normal? How do I properly adjust the 2 adjustment screws in the regulator. I understand alot of electronics, but I'm out of my element here. I have replaced the wire harnass with one I made, triple checked all the wires when I was troubleshooting the generator.

I am happy I got the generator to work!! I'm just concerned with the system working properly now. Charging a battery at 20amps, when it is already fully charged from my float charger, for a long time can boil the water right out of it and warp the plates.

I thought about putting an alternator on it, but thats alot of work between the bracket, the reduced pulley installation, the wiring.

I actually have a float charger I keep on the battery when not in use to keep it maintained. If all else fails, I wouldnt be against just having the generator on when the lights are on. Without the lights on the battery will run the tractor for far longer then I'll every use it continuously.

I hope some of you guys can give me some detailed regulator adjustment instructions or advise on what to do.

I really do appreciate all of your guy's help. I've been on some other tractor forums, and you guys are by far the nicest people.

1 - Ground the generator ARM terminal. Then use a 6 or 12 volt battery to supply current to the FLD terminal (ground thru the generator frame). If the armature spins the generator is probably OK.

2 - Ground the FLD terminal. Now spin the armature to 1,800 RPM or faster and take a voltage reading between the ARM terminal and the generator frame. An output reading of 18 volts or higher means the generator is OK.

Note - The above will tell you whether or not a generator is completely DOA. However a generator can pass the tests but still have problems with low output, etc.

Regard it rather as a screening, or "go/no go" test for an unknown generator!

You might double-check to see that your regulator is properly grounded in light of what I have described. That small ground strap is not very obvious - but your regulator may not be rubber-mounted and need one.

1) If that Voltage Regulator reallyyyyy y has 4 terminals as you implied, especially if ones off on a side or the bottom all by itself, sounds like you have a 4 terminal (BAT ARM FLD LOAD) Voltage Regulator instead of the 3 terminal (BAT ARM FLD) VR but thats NOT a problem regardless which you have, we can make it work. Often on those its the ARM terminal thats off all by itself, hope you have it wired correct???

BAT to Load (NOT to battery/starter) side of Ammeter ARM/GEN to gennys larger ARM post FLD to gennys smaller FLD Post LOAD wires up to the dash and feeds hot batery voltage to the BAT input terminal on the light and ignition switches.

In the event its really only a 3 terminal (BAT ARM FLD) VR, loads like lights and ignition receive their hot batetry input voltage from the ammeters Load terminal (same that wires to BAT on VR) instead of from the VR's LOAD terminal as just described.

The 3 terminal VR wires as follows:

BAT to load (NOT battery/starter) side of ammeter ARM/GEN to gennys ARM post FLD to gennys FLD post

Nowwwww heres the deal, if its really a 4 terminal, or even if only a 3 terminal VR, it may have 3 instead of just 2 internal relay/coils. Ones the Cutout Relay, ones the Voltage Control Relay, ones the Current Control Relay. If it just has 2, as Jim noted, ones the Cutout Relay and the other is often EITHER a Current Control orrrrr a combination Current and Voltage Control

SORRY not knowing what VR you have and with no specs or data I simply dont like to give advice on tweaking any VR here on the net, its hard enough if on my own tractor and armed with a good VOM AND IT MAY INVOLE ADJUSTING SENSITIVE AIR GAPS IN CONTACTS AND/OR BENDING TABS OR ADJUSTING SPRING TENSIONS EWWWWW WWWWW NOT A JOB FOR AN AMATEUR ESPECIALLY ABSENT ANY SPECS OR DATA.

HERES MORE THOUGHTS: While EITHER a 3 or 4 terminal VR can be wired n made to work, the 4 terminal is supposedly better at finer regulation and better at preventing potential overcharging PROVIDED its wired and used as intended.....THEREFORE if it really is a 4 terminal and ifffff lights n ignition are now fed from the ammeter versus the LOAD terminal on a 4 terminal VR IT MAY HELP IF YOU REWIRE THE LOADS OFF THE VR LOAD TERMINAL !!!!! !

Keep an eye on the battery acid to insure its not boiling over nor is there a lot of Hydrogen or Sulfur smelling outgassing, indicative of overcharging. Right after start up Id expect the charging system to go at full charge say maybe 7 or so volts buttttt tt after a long time if no lights are used Id expect it to back off to more like 6.5 or so volts. If it stays at 7 volts constantly the VR may be at fault or need adjusted and/or the battery may be the problem cuz a bad cell may be causing it to contiuinually try n charge at max rate?? Is there electrolyte above all the plates and no cells have a gray or milky color????

NOTE AND DISCLAIMER: Im NOT an IHC man, just knee deep in theory buttttt t seems the 4 terminal VR's are more on the 12 volt systems????? Bob and Bob M and Jim are way more knowledgeable on what systens what tractors used, sooooo ooooo if they say they didnt use 4 terminal VR's on 6 volt systems, BELIEVE THEM !!

That being said, even if its a 3 terminal VR, she may still be overcharging or the battery may be at fault and the advice regarding that still holds true. Still, if she dont boil over and the battery is good n shes not outgassing badly, YOU MAY NOT EVEN HAVE A PROBLEM?????

John T

John T

My recommendation is to replace the voltage regulator with a new one. Properly adjusting a VR requires specialized equipment and is kinda fussy to get right. However if you wish to attempt to reset your existing one here’s how:

1 – Remove the regulator cover and identify the voltage regulator relay (it’s the one with the coil wound with many turns of fine wire and with it’s contacts held CLOSED by spring pressure.)

2 – With the battery fully charged, start the engine and let it run at governed RPM for 5 – 10 minutes to stabilize the battery and get the generator to operating temperature.

3 – Connect a voltmeter across the battery posts. Now gently bend the regulator relay spring hanger (or adjust the adjusting screw if provided…) to slightly REDUCE the spring pressure then check your voltage reading. Shoot for a reading of about 7.2 or 7.3 volts. TIP! Make adjustments in small increments! It takes only slight change in spring pressure will make a dramatic change in voltage.

4 – When you a finished the voltmeter should show 7.0 to 7.5 volts and the ammeter should indicate around 5 amps at full RPM.

Good luck and hope this helps!

If you want to change the gen. go to a two brush, and attach it the same way. Good luck, JimN

Once again, I appreciate the help and so does big red =P