trane 3.5 ton heat pump unit runs fine in ac mode (compressor working fan etc.)
switch to heat - usual delay and then short buzz 1/2 inch move on the fan and both fan and compressor go silent!
switch back to AC and A/C is working -- back to heat and - BUZZ - nothing
i suspect he starting capacitor but i'm almost positive the same capacitor starts the ac and heat cycles.
em heat works fine (because it has nothing to do with the outside unit