Air Conditioner runs but won't cool

finally got it. between switching the two lines on controller board and running a new yellow wire for the compressor to the controller board it worked. thank god, the way home will be MUCH better now.

adambeck7 wrote:
yellow wire has power leaving the thermostat but not when it reaches the controller box...

The yellow wire is open somewhere. USE the unused white wire and connect it instead of the yellow. Also, cut the spade terminal OFF at the AC control box and test the yellow again. Sometimes, they crimp and the insulation stops the copper to spade connection. Or they neglected to strip the yellow before crimping. Doug

yellow wire has power leaving the thermostat but not when it reaches the controller box...

You're awesome Doug. Thanks. I'll grab a 12v circuit tester and post back.I'll post a pic of the t-stat wiring too. I'm a little color blind so it's tough for me to tell.

adambeck7 wrote:
Doug, no LED's but here's two pics of the board itself and the wiring diagram. within the compressor relay the "NO" (black wire) had power but the "COM" (Purple wire) did not.

The BLACK is the 120 hot feed to the AC board. The Purple goes to the start capacitors. That black box is the relay that CLOSES to supply 120 power to the purple wire. So, If you have it set for COOL and no 120 power to the Purple wire, then the odds are the wiring between the tstat and the control board is open or miswired. It is extremely RARE for a wall tstat to be bad, it is 99% the wiring. It takes 12 volt power to close that compressor relay. In the shop, I would apply 12 volt power to the "Y" spade and see if the relay closes. Before that, I would check for 12 volts on the "Y" feed wire from the tstat. Doug

Doug, no LED's but here's two pics of the board itself and the wiring diagram. within the compressor relay the "NO" (black wire) had power but the "COM" (Purple wire) did not.

i'll give that shot doug, thanks.

Didn't work shorting the freeze thermistor didn't help. Don't have a 12v circuit tester.

Unplug it and jump across the terminals- won't hurt anything. That is where the sensor is supposed to be.
You can also check to see if the yellow wire has 12 volts on it (while calling for cool)- if not, it's in the thermostat or t-stat wiring.