Diagnosing Battery Discharge

[Kevin Trent <trentkc@domain.elided>]

Last fall my '73 spider developed an electrical drain that will discharge
the battery overnight.  I used my  multimeter to measure the drain and found:

1.  a drain of about 3 amps (I think - if I read the scale correctly).
2.  removing each fuse in turn had no effect on the drain.
3. disconnecting the big read wire to the alternator from the battery
eliminated the drain.

The alternator has been rebuilt in the past and now incorporates a small
"transistorized" voltage regulator mounted on the back of the alternator.
This eliminated the standard regulator, and makes the alternator a "one
wire" unit.  Despite the drain when shut off, the alternator charges at
14.5volts when the engine is running.

My question:  Can my alternator and/or its now integrated voltage regulator
have some internal short that is causing this battery drain?  Or is my test
logic and diagnosis faulty?

Thanks,  KCT,  Powell, Tennessee   (where its been sunny and 70 for two
weekends...)

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