>.....  Any Suggestions?
Eggz:
I had the same symptoms with my '81 Van (with 75K) in the mid-eighties.  I
kept thinking battery, coil, ground or starter solenoid; but the starter
motor (windings) was shorting out once the engine was warm.
A rebuilt Bosch starter did the trick. It was still going strong when I
traded it in several years later.
Not sure, but hope this helps. Also, it might help if you listed the year,
mileage, etc.

--
Stephen
Chillicothe OH