Super frustrating AC issue

dougrainer wrote:

kfp673 wrote:
Yes we have ceiling mounted controls. I accessed every panel that I could find including everything on the roof to make sure all wires were secured. I’m not sure specifically where the thermostat wire connects but I will continue to look. What I can say is there is a harness that plugs into the ceiling assembly directly. That harness runs up to the top unit. I disassembled the entire top unit to trace those wires and they all run either through the capacitors or to the fan motors etc. Is there a place on the indoor unit other than that harness connection I should check?

It concerns me that you stated you did NOT see the tstat wires. Those are on back of the rotary tstat and access is just removing 1 screw to expose the inside of the Galvanized tstat housing. The ON/Off Fan speed switch on the other side has the same cover that will expose those wires and spade terminals. Now, you state (hopefully you were frustrated), POS. Well, you do NOT know what you are doing and your posts support that. So, until you verify it is NOT your install problem don't blame RVP. That multiwire quick connect is standard going from your interior control assbly to the roof top unit. Really need to know the MODEL AND the Lower control package number. The standard RVP the PURPLE wire in that quick connecter should have 120 VOLTS when you select Cool. If you do NOT have 120 volts on that purple wire, then you have a Selector switch or tstat wire problem. TEST THE PURPLE WIRE FOR 120 AND GET BACK TO US. Doug

Thanks. I appreciate the scolding and will be sure to keep this in mind next time I need to spend 10 hours trouble shooting something with a single wire harness.

Yes, since that post I have removed the T-stat and checked all wires plus the system selector knob. Also pulled apart every panel on the roof side and checked every connector. I am 100% positive there are not lose wires at this point. This direct vent AC is very simple and really should just work. Connecting the harness from inside to out and AC power is literally all that should be required other than the obvious physical mounting. Anything else and yes, its a POS with very poor QC as are almost all parts made for RV's. I will test purple wire in the harness for 120V as you have suggested.