YM1500 Electrical Question

[NCDaveD]

I've been trying to find out why my YM1500 doesn't seem to be charging and think it may be the voltage regulator. I checked the dynamo and it put out the following AC voltages: 15.8@ 1000RPM, 20.3@ 1500RPM and 27.6@ 2000RPM. When everything is hooked up, I'm only getting 12.5VDC at the battery with the tractor running(same voltage at different speeds). I took a look at the regulator and sure enough, the output wire was broken clean off at the rubber bushing on the regulator. Strange thing was, the only wire it could have hooked to was not connected to anything else. I checked every connector and ground on the tractor, and never found the other end. So I figure I have to run a new wire from the regulator to the wire between the ignition switch and starter (according to the wire diagram, that is where it belongs). And yes, somewhere in the tractor's background SOMEONE did some rewireing as it has a new fuse block that was not wired up correctly (had both turn signals and headlights on same circuit..I fixed that).

So my question is, are those good numbers from the Dynamo (seem high to me), and is there the possiblity that the dynamo on the tractor uses the 3 wire regulator and not the 4wire? The original with the broken wire had 4 wires (1 broken).

Thanks, just want to be sure here...

NCDaveD

 

[MDA1775]

The voltage at the battery is a composite of the alternator and battery voltage so it will not increase much with the increase in RPM's, what should be happening with the RPM increase is an increase in available charge current. When a charger or alternator/dynamo is charging the battery the voltage will show a slight increase above the battery's resting voltage (no charge applied) then as the battery gets recharged the voltage will rise and the current will decrease. So check your battery's resting voltage and see if it is still about 12.5 if so you are not getting any charge input. Also most alternators (not sure about yours) won't put out more than 13.6V when operating properly, more than that and they would gas the battery so badly you couldn't keep water in it.
That's a general overview. Good luck

 

[winston1]

Sure not an electrical guru or any kind of guru but am full of opinions. I think your AC voltage is fine. Hoyes shows the 4 wire regulator for your 1500. Yanmar Tractor Parts: VOLTAGE REGULATOR_ I believe I would do as you are and that is to hook it all back up per the wireing diagram.