Cooline splilt-Outdoor fan not working in heating

[Benjimo]

I'm trying to sort out a problem with a Cooline split air conditioner that's starting to do my head in. The outdoor fan isn't working when the system is set to heating, but works perfectly well in cooling. I have tried switching the sensor on the outdoor coil and the indoor circuit board over with the same unit next to it but to no avail. There aren't any pressure sensors, only temperature probes adn when disconnected the unit stops. The unit works normally, but the outdoor coil ices up because of the lack of air flow. The Model number of the indoor unit is MWC24EHXGI, outdoor unit MKC24BSTHACI.
Just wondering iof anyone had any ideas of what the probelm could be.
Thanks

[Yuri B.]

Hello Benjimo.
Then what is left to check is the indoor coil's pipe sensor (you have not mentioned trying it - taken from the another unit). I believe it is bad.

[Benjimo]

I tried changing hte indoor sensors over, but it didn't change anything. I ended up running out of time so wired the outdoor fan into the compressor contactor. Not the desired result, and I really wanted to nut it out but it works all the same

[Yuri B.]

There are 2 indoor sensors - one (air in temperature) - in front of the evaporator , another (evaporation temperature) in short tube loaded to the evap and pressed to the pipe with a spring.
Patiently check everything - fortunately,you have the "source" of the parts at hands (the another a/c).

[paul_h]

How many wires to the outdoor fan, how many speeds is the motor?
Just asking because it might be a two speed fan, and the indoor PCB might run high on cool and low on heat. So could be a fault with the motor, interconnecting wires or PCB relay on the low speed setting.

If only a single speed motor, then the control logic on the PCB is not switching the relay for fan on heat mode, so faulty PCB.

[FreonDon]

Have you checked the gas charge, the fan is controled from the board by the temperature sensors, if the gas charge is correct the fault could be either the board or the sensors.Had the same fault on an old high cool.