I have a Series 2a with a generator and my battery gets drained as I drive. I put in a new voltage regulator and had the generator bench tested which passed. I am only getting 12.60 reading at best going into the battery. Could it be that the generator is putting out 12.60 but not enough to replenish the battery as the juice is used?? Any help greatly appreciated.

 

Well, this is a case of older design and newer batteries. In a modern vehicle, the expected voltage is 13.6 - 14.4. Now that voltage is determined by the load on the generator. My D1 puts out one voltage at idle, and somewhat less at "everything switched on". But I don't drop below 13.2. IMHO 12.6 just is not enough to charge the battery up in a reasonable period.

Might want to have generator tested again. Maybe by a starter/alternator shop instead of teenager at the parts store. And yes, there are very smart teenagers. Just not enough.

The alternators in modern vehicles are actually a three phase AC generator which has rectifiers to convert that to DC. If one of the diodes is out, you drop 33% of the amp capacity. So it can read good volts until you start turning things on.

On the older units with a "vibrating" style regulator, they had three phases as well. So one phase can be bad and you would have low amps. The Series 2 military vehicles has either a 40 amp or a 90 amp AC/DC generator.

See Installing a Delco Alternator in a Land Rover Series IIa | Christopher H. Dow

and The Canyon Product 2

Owners do put in Delco larger alternators. Of course a jump from a 40 amp to a 90 amp may have you making up some new harness wiring in spots.

A 40-43 amp alternator won't run much. But in fairness you don't have a lot of the more modern electronics drain.

 

Thanks for the reply. I did take it to a starter/alternator shop and it passed. I just checked myself and its getting 14+ coming out from the generator and still 12.88 at the battery - with new voltage regulator. Is there a ground issue between regulator and battery?

 

Follow the negative battery wire and it will bond somewhere to the frame. Will likely need to be scrubbed bright and re-attached. You can also try adding a bonding jumper from (-) battery to the engine block. This can be done as a test with a batery jumper cable.