6 Volt NAA Overcharging

phil(va)

Well-known Member
Tractor was not charging battery. Showed same voltage on battery running and not running and ammeter at zero. Had reliable shop check
generator and they said nothing wrong with it. So I replaced voltage regulator (VR). Now it is over charging, showing close to 30 amps on
ammeter and 8.9 to 9 volts across battery. Checked ground at VR and genny and both show good continuity to battery ground. Suggestions?
 
New voltage regulators. most likely from China are sketchy at best.
The points are adjustable to get the voltage to about 6.3 volts . You have to bend the tab slightly. Making the gap larger should lower the voltage, IIRC.
 
Put a charger on the battery to charge it up first. Then start the tractor after battery is charged to see what it does.
 
Most likely junk offshore regulators. They are theoretically adjustable, but that requires a lot of patience. Might be better off trying another one and crossing your fingers. Ideally you'd like to see around 7 volts max charging rate. 9 is gonna boil the water out and maybe even make it go boom.
 
I thought there was a thread a while back about the same problem and it ended up being the generator was overcharging with the VR cover on. When he took the cover off, it charged normally. Maybe do a search.
 
I wish I had known about the Brillman Company a couple of years ago. I ended up converting to 12 volts after going through 3 junk regulators. Yes Tim the wiring was correct. I had been running this tractor for 20 plus years before this.
 
Got it fixed. It was the voltage regulator. I took a chance and removed the cover with the VR hooked up on the tractor and 'tuned' the VR by trial and error, and got it to charge, finally. Had a tough time getting it to settle at 7 volts. It wanted to go high or not at all, and it definitely changed each time I put the cover back on, so it was very frustrating. Probably had a couple dozen tries. Unhooked battery each time I adjusted. At first I tried to adjust by moving the points up or down by loosening the screw (on field connection). But best way was to bend the spring connection. Just following up, fyi, in case anyone is interested. Thanks for your input. This is not a task to be done with the hood installed.
 


I can remember the old mechanics talking about the metal cover on VR's... They said the voltage would change by one volt with the cover off vrs the cover on. So they allowed for that when the set the VR.... Trouble is.. .I am not sure which way... I think.... they said it would read a volt higher with the cover off.... but thats pretty fuzzy now. And that not all vr's did that.
 

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