[whited44]

If you have three compressors you need 3 relays.

The fan function was not changed only the compressor function.

If either fan fails to activate, the compressor will eventually overheat tripping the circuit breaker. Adding the external relays will do nothing to address this issue.

Let’s determine why the fan is not turning.
It could be a faulty capacitor for the fan.
It could be a failed circuit or connector on the circuit board.
It could be a failed fan motor.
It could be a faulty thermostat.

Is it the indoor or outdoor fan that is not working?
Do you have the SCS manual, excellent trouble shooting steps in the manual.
Are you comfortable working with live 120V?
Will your multimeter test capacitors?

Oh Richard..  I love your questions. They always involve a meter.  I loathe the meter. My dad was always the electric guy and he would just tell me what to do.  He’s too old now and it’s forcing me to learn how to use it.  

The living room unit (outside rear) will run for a while.  Cool, inside and outside fan running.  But after about 1-2 hours the fans (both) will shut off however the compressor stays running

The bedroom unit (outside front) has 2 breakers. When I flip on the breaker 1 nothing happens, when I flip breaker 2 I can hear the compressor run, however no inside or outside fan.

How do I test the capacitors??
What shall I look for on the board??
I “think” The thermostat is ok
I do have the SCS manuals
I have a pretty nice meter but I don’t know where to run the knob to ?