flathead genarator help

im runnin a late merc motor witha 12v genarator and my battery isnt charging i get over 13 volts but the battery wont charge and actually seems to drain when the car sits. everything worked fine for a long time and latley its been doing this any ideas? is there supposed to be a diode between the regulator and battery? wire guage? i know how to polarize the regulator but how du you polarize the generator?
thanks

 

If you have 13 volts, and the polarity is correct. Check the out put under load( all accy. on, lights etc.) if you have access to a clamp on amp. meter check the amp. output with a full load. Have the battery load tested, your problem may not be charging system related. Check for draw from accessories with the key turned off.
Hope that helps.

 

There is a cut out in the regulator. If it is stuck shut it will drain the battery but it will also fry the generator. IF you put power to the generator it will try to turn and if the v-belt is on it, it can't therefore the magic smoke will escape. I am guessing you have a bad battery or a drain from something in the system. Unhook thing until you find the voltage leak.

Neal

 

Sounds like bad battery. If its charging at 13V, its not a polarization issue. Load test that battery and I bet you find the problem.

Oh, and for future reference you're not polarizing the regulator, but the genny when you jump from BAT to ARM on the regulator.