The other night I woke to the sound of the service air blowing but no compressor. The blower would not shut off nor could I turn it off at the thermostat-had to turn it off at the unit. Code light is flashing "6" which is reverse polarity or bad/weak ground. We had some good thunderstorms earlier in the evening but I believe everything was working normal before bedtime. HELP, IT'S HOT...
Monty

It's a trane by the way...

I would start by checking the circuit breaker in the house and then check the fuses outside in the disconnect if the disconnect has fuses in it.

OK, Now the service air appears to have healed itself. Turns on and off at themostat with on/off switch and temp selector. Relay on outside unit closes but nothing else happens. I think I have 220v at compressor but will check. Anything else that will keep the comp. from coming ON.
Thanks, Monty

You may not have power at the out side unit if nothing runs, there should be fuses in the disconnect near the unit and also check breaker, if this is not the problem remove the access panel on the outside unit and very carefully push the contacts in on the contactor with an insulated object like a screw driver, if if does not run you have no power to the unit if it does run you may not have 24 volts control voltage to the unit , this comes from the furnace or air handler. Good luck

Well, I am beside myself now. I had 24v at the unit, the contactor was closing but nothing. Went inside to turn off the system, came back out to check for 240v, for the heck of it I pushed in the contactor and violia, the fan and compressor came on. The only think I did other than that was excersize the 220 breaker at the outside unit. It wasn't tripped as I had flipped a few times before and it felt a little funny but who knows what it was. Dirty contacts, little gremlins etc. Thanks for all your help. Monty