642-Battery Not Charging

[bfingar]

I pulled the 642 out of the garage the other day and the voltage gauge on the dash was reading low. I put a volt meter across the batt when running and it read about 12.5 volts. I know it should read around 13.8 when running and charging.
I have the service book for it, but I have not had a chance to look at it yet. I know the machine is a 12 volt machine and the ignition is 6 vdc. Is the voltage regulator in the alternator or is it hanging on the left side of the engine in the same vicinity as the ignition resistor? I am assuming it is in the alternator. It is probably time to have it rebuilt! Of course, it could be just a bad connection! Those are more fun to find!
Bernie

 

[Tazza]

Most alternators have the regulator built into the unit. It could well be a bad connection, you may want to try and runa w ire direct from the battery +ve to the back of the alternator just to be sure as it could be a blown diode that feeds power in too.

 

[bfingar]

Most alternators have the regulator built into the unit. It could well be a bad connection, you may want to try and runa w ire direct from the battery +ve to the back of the alternator just to be sure as it could be a blown diode that feeds power in too.

Last night I had a few minutes to check voltages at the connections to the alternator as per the service manuals instructions. Everything seems to be ok from a connection/voltage measurement point of view. Which of course means the alternator needs to be rebuilt. I still have a few weekends of work to do, so I guess I will just keep the battery charged and run it for a few weeks on the battery until I have some downtime to pull the alternator out and get it repaired.