Alright another update. So after I replied to FFD with a long winded email of tests performed, and requested the resistance parameters of the probes so I know what to look for testing them. They replied "were gonna go ahead and send out a new controller" lol.
I'm not even gonna use it now (going w/ fixed temp sensor) but will go ahead and leave positive feedback, at least they back their product.
Maybe I can use it on something else...will toss in electrical junk drawer...along with all the other leftovers from this project
A fixed temp sensor should be a switch and have two connectors, and the two connectors are OPEN, High OHMs(N/C) or CLOSED/Connected, 0 OHMs, direct connection
And neither connector is connected to external metal of the sensor/switch
If this is the case then you can use the same 12v activation for the fan relay AND AC activation for the fan relay
One temp sensor wire to the blue wire(on fan relay) and key on 12v fused wire to other temp sensor connection
For AC you need a DIODE to connect it to the Blue fan relay wire
A Diode only allows electricity to flow 1 way, in this case from AC clutch 12v wire TO the fan relay's blue wire
If you don't use a diode then any time fan is activated by the temp sensor the AC clutch would get the same 12volts so AC compressor would come on
The diode prevents the temp sensor's 12v from traveling back to AC's Clutch, but still allows the 12v AC to activate the fan
Generally you would use Ground activation of the Fan relay with a temp switch, but then you would need another relay to add the AC "fan on" to the system, a diode is cheaper