I have been having an intermittent Rheem air conditioner/
heater problem. The blower won't shut off unless I cut
the main power. The furnace shuts off fine. Switching
off the fan or anything on the thermostat won't shut it
off. The technician says that they won't repair it unless
they find it dead. By the time the technician arrives the
AC is working again because it usually fails at around
1-4AM then resumes working again at 5AM.

I am now deciding to replace the parts myself but
need some help. I'm not certain but I think the
symptoms point to the blower relay D7 or the fan
cycle control switch F7 on this schematic diagram
http://www.freewebs.com/acrepairs/RHEEM.jpg.

Where is the fan cycle control switch is located in the
Rheem heater - is it inside the furnace?

Thanks
Tim