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Goodman CK36-18 problem

7K views 22 replies 4 participants last post by  beenthere 
#1 ·
My AC worked great all summer and quit cooling the other day. The compressor isn't coming on and the fan isn't turning. I have 24 volts on each side of the contactor coil (new) and I replaced the capacitor. When I close the contacts manually, the compressor comes on. Any ideas on why the contactor contacts aren't being pulled closed? Thanks!
 
#11 ·
Then you have lost the return or common (C) wire from the outdoor unit back to the furnace. Check the wiring where it leaves the house to the unit. Got damaged/got chewed by rodents/dog/wheedwacker.
 
#2 ·
Contactors can be finicky if you twist them or stress them. Plunger can stick. If the high voltage wires are tight and the body of it is under torque it can stick. Try loosen them and start over. Your furnace transformer may be weak or you have loose/corroded wiring connections somewhere. You can have 24 volts but a poor connection can prevent current flow.
 
#3 ·
Gotta agree...

If you have a solid 24volts at the contactor than either the new contractor is bad or you have a transformer or wiring problem.

There are no other safetys in the 24 volt circuit (i.e. low press cut out in case of freon loss) unless they have been field added.
 
#4 ·
Thanks Yuri,

I took the contactor off and replaced it gently, making sure I didn't distort it. I also removed the 24v wires and cut and restripped them and didn't notice any corrosion. It still won't start up unless I manually close the contacts. :(
 
#6 ·
Thanks hvaclover! I'll have to crawl up in the attic and check the transformer and wiring. I just received the contactor via ups yesterday so I hope it's not bad. The ac ran fine last year too until August and then died. I just left it alone and this Spring when it started to get warm I flipped the switch and it worked all Summer long until now.
 
#7 ·
If you have 24 volts on both sides of the contactor. Your not checking for voltage correctly. You don't check from the contractor to ground, or common. You check from one terminal to the other..

You probably lost the common somewhere.
 
#22 ·
:thumbsup:Thank you thank you thank you!!!!!!!!:thumbsup: You guys are the best! It looks like a squirrel chewed the wire where it enters the attic. I replaced the wire and am sitting in coolness!:thumbup: I really really really appreciate all your help and patience! Thank you!

Tammi
 
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