Hi everyone,
I have been attending alot of u4 faults on daikin inverter systems and all of them (about 20 now) have blown the inverter board from the fan motor. The problem I have is when I get on site with this fault code and the inverter is dead I just meter out the compressor and then cange the fan motor and inverter and bingo it all works. I don't know if my fault procedure is correct but it seems to work until I come across a twin blower when I just replace both so my question is how does anyone meter these motors out when it is impossible to get your multimeter into the pinholes on the plug daikin just say I get what u mean but here are the resistance readings anyway. I tried chopping the leads once but the wires were so thin the results were inconclusive.