A/C Won't Turn On - No Power to Thermostat

[TFA303]

HELP!!

(Wife isn't pregnant, but my ability to reproduce may be threatened if I don't fix this...)

Subject line says it all. This is a central A/C attic unit. I've checked power to the A/C itself, circuit breaker, power out from the trasformer is 24v, all the easy stuff.

The thermo has no reading with the multimeter. Any suggestions?

TIA,

Tom

P.S. Love this site; Samurai Appliantlogy hooked me up with my dishwasher and refrigerator.

[applianceman18007260692]

the outside unit is noting more than a compressor and a fan motor . what brings it on is called a contactor . the contactor is basically a big old relay that powers up the outside unit. it had tiny wires that fire this mutha up from the inside by the 24 volts . check the coil on this contactor to see if its got continuity if its open its bad. If you manually push down on the contactor and the outside unit responds then it MAY be the coil. a quick redneck temporary fix is to jam a popcycle stick in it and make the outside unit stay running, not recomended by me ,but if its hot as hell you gotta do what ya gotta do ,you know ?

 

[TFA303]

Many thanks, applianceman, will try that.

Tom

[AccApp]

The with thermostat in "Off" and "Auto" should have ~24v between red wire and any other (white, green, yellow/blue). If no voltage at red wire you have a bad wire to t-stat. Start fishing.