two-part heat pump. no matter what is set on the thermostat the fan is
running.
I removed the thermostat off the back plane, no difference. The only
thing that'll stop it is the breaker which is a two pole.

My guess is the fan relay is stuck on the heat pump maybe the
contactors welded closed.

I suppose the best thing would be to go up in the 'attic' and inspect
the relay, and if it's damaged, get the p/n off it and buy another
one.
I'm not into burnishing pitted relay contacts. I'm also assuming at
this point that the fan motor is not drawing excessive current
because it is indeed running, and not tripping the main breaker or
any protective breaker which might be in the heat pump. I do not know
yet because my son-in-law has to empty the ton of junk out of my way
and eradicate the hornets or whatever they are so I can get up there
and take a looksee. Comments?

RED SOX 7
STANKEES 4

Homers by David Ortiz, Alex Cora and Manny Ramirez led the Red Sox to a
7-4 win over the last-place Yankees on Sunday that guaranteed Boston its
largest division lead through April in franchise history. Jonathan
Papelbon pitched the ninth inning for his eighth save.