<VV> 64 run circuit problem Resolution

[Smitty]

Smitty says;  Finally after all these months.  We had checked voltage at the coil many times but never continuously while the engine was running.  Darned it didn’t start dropping the closer to the 20-30 minute time frame it got.  Finally down to 4.5 volts and the engine died.  OK so we got a new clue, but still no answer why.  Now we noted that the voltage on the big red wire going forward through the belly pan was dropping also.  We had read out the wire from the coupling under the dash and back to the coupling in the engine compartment and all seemed well.  Except of course we had been reading it when nothing was operating and things were cool.  Now we knew to measure and feel for heat in the couplings when the engine had been running for a while.  Sure enough. heat build up in the forward connector.  The red wire and another pin showed evidence of corrosion so they were well scraped and cleaned and treated with contact cleaner.  The connector was coated with dielectric grease and put back together.  No more voltage drop at the coil.  So the initial problem was solved but it leaves me with a question.  Why was that making the ballast resistor overheat.  Maybe one of you electricians would enlighten me.