Central air not working

[edsjr]

So I get home and decide to turn the air on.....I made it longer than most!

I close all the windows and switch the thermostat to cool, the furnace kicks on. Go outside to get the lawn mower to mow the front yard, thinking I would come back in to a cool house.

Get out the back door and the A/C unit is buzzing. I stuck a stick in where the fan is and turned the blade thinking maybe the motor was hung up. The fan turned easily.

I cut power, took the cover off and sprayed everything out real good then turned the power back on.....same buzzing. It is coming from the switch where all the wires go into.

With the power on I tapped everything with a rubber mallet a few times (couldnt hurt, right?).

Anyone have any ideas if this is one of those easy electrical fixes or am I shopping for a new compressor?

Thanks
Ed.

[Ed Imeduc]

Can be the contactor there. Do you read 220V in and out of it when its pulled in and buzzing??? forget the hammer get a meter. :D

ED ;)

[hiltontech]

Bad contactor, also Ed is right, forget about the hammer, won't do any good.

HiltonTech

[edsjr]

Had to try the hammer......just on the longshot there was a piece of crud blocking a contact an it would jar loose. For the record, that was about 1 minute of my efforts!

Spoke to my uncle and he agreed the contactor is more than likely the culprit, he had me cut power and clean the contacts on the little deal that goes down to see if that would cure it. I cleaned them for a few minutes (kind of a PITA) and then sprayed them with brake cleaner to remove the dust and shavings.

After cleaning, I restored power and still nothing but the buzzing. The little plunger thing goes down and makes contact but I didnt get it shiny so I still dont know if there is contact.

The unit is probably 20 -25 yrs old (old rheem) I am in the middle of a huge remodel and would rather put replacement money somewhere else.

Is there any possibility the contacter could still be bad? If so, that looks easy to replace.

My Uncle also spoke of a fan starter.....is that a possibility?

Thanks
Ed.

[Grady]

First you need to verify you are getting 220 volts to the unit. If you are, the problem could be the contactor or the capacitor. Since you filed the contactor points, you should replace the contactor. There is just a plating of silver or gold on those points & now it's gone.

[edsjr]

so sanding them with emery cloth was bad?

where is the capacitor? Is that the little tube shaped thing with two red stripes and one yellow one on it on another piece?

I have a very good picture of the whole thing, is there any way to upload it here? Could I email it to you?

Thanks
Ed.

[mattison]

Before doing all that get a meter and confirm you have line voltage at the contactor and coming out of it.

[hvac guy]

20 to 25 years old? forget the rubber mallet , get the sledge hammer .time to up grade