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leatherman · Aug 13, 2013, 06:40 PM

Replaced the condenser fan motor, and both capacitors. Unit will run for a few minutes and the fan stops, the compressor is noisy as well. After the last test run I saw what looks like a relay pop out a little after I turned off the power. Its on a black block where all the wires connect to. Is this the problem? And what is that box called so I can order a new one if possible.

At first I thought I may have wired it wrong, but I don't think it would run at all if I did goof that up?

This is an old central air unit, but I want to keep it running as long as possible.

Thanks for any help.

Johnson64 · Aug 13, 2013, 07:52 PM

The black box will be either your contactor or relay. If you have had any power surges a storm recently that might be your problem. Best thing to do is to get it tested.

leatherman · Aug 13, 2013, 08:08 PM

Thank you so much! Its one of the last things besides the compressor to replace now, well, that and the blower motor inside. Nickles and Dimes.

Edit to add: if anyone has anything else I should be checking or replacing please do let me know, its August in Texas and we're getting desperate but not much money limits our possibilities.

leatherman · Aug 14, 2013, 09:45 AM

Originally Posted by leatherman

Thank you so much! Its one of the last things besides the compressor to replace now, well, that and the blower motor inside. Nickles and Dimes.

Edit to add: if anyone has anything else I should be checking or replacing please do let me know, its August in Texas and we're getting desperate but not much money limits our possibilities.

Did some more testing this morning, the relay works correctly, but shows some blackening around the contacts. With the power off to the condenser the inside unit turned on the relay closes nice and firm, when the inside is turned off it opens with authority.

Note from yesterdays testings, the motor gets HOT before it stops after a few minutes. After some research I have a whole list of things to check. The two capacitors are new, but should probably be tested, that said is there a front and back on the two poles on these things? I've read about reversing the wires but I don't want to try that until I'm sure I am not going to blow it up.

It seems that, from what I've researched, its down to capacitors or wiring, and maybe that switch. Wondering if I should take them all to the Grainger for testing. Lots of wires to keep track of though.

leatherman · Aug 14, 2013, 04:07 PM

Well, I did replace the contacter, and the condenser fan motor still stops after a few minutes.

I'm at a loss, over 200.00 and not any improvement.

Johnson64 · Aug 14, 2013, 06:25 PM

If there's a Grainger near you then sit in the parking lot and wait for a Heat & Air guy to show up and ask him... from my experience with them they will give you some advice

Grady White · Aug 14, 2013, 06:30 PM

You replaced the condenser fan motor & capacitor but are you sure the cap is the correct one for the motor? Just because it was the same as the old one means nothing. The cap has to be matched to the motor.

leatherman · Aug 14, 2013, 07:31 PM

So far so good, I reversed the wires on the capacitor, brown/white and solid brown as per a suggestion and its humming along now.

The guys at Grainger matched the capacitor and motor at the store thank goodness. I have honestly never been to a parts supplier, auto and such, that were as knowledgeable as these guys are. I am a very happy customer, and their tech support is second to none.