Thread: Central AC not working walk through

Great info for those who have a little clue about VAC. Thanks, Mike. One other thing to check before you break out a meter is...
Most AC units outside are wired to an outlet that is outside. These outlets also have built in breakers. So be sure to check it too before taking the unit apart and getting out the meter.
Its more of a quick disconnect then a breaker but take a good look.

Originally Posted by Gasman

Great info for those who have a little clue about VAC. Thanks, Mike. One other thing to check before you break out a meter is...
Most AC units outside are wired to an outlet that is outside. These outlets also have built in breakers. So be sure to check it too before taking the unit apart and getting out the meter.
Its more of a quick disconnect then a breaker but take a good look.

Yep, mines gotta fuse. Though, I did have a capacitor go bad, once.

The bulge and burn marks made it easy finding the problem.

Replaced it for mere penny's, compared to the price of called a specialist.

Good points gents..
Also figured I might as well add that if everything checks out, and your contact works too, to check the compressor itself use your meter, on resistance setting to check the three leads going to the compressor itself.
With all three disconnected from the circuit you should have 3 different ohm readings between the wires.
Ie, between 1&2 you get 1.5 ohms
2&3 you get 2 ohms
1&3 you get 3.5 ohms, means it’s a good compressor.
So the total on one leg should equal, about, the sum of the other two legs,, rule of thumb. Anything open or far off these numbers means bad windings in the compressor after all.. at that point call a specialist..
Cheers.

Bulging caps are a good way to tell for sure. But be careful playing with caps. They store power and can bite. Badly! Enough to kill you in some cases.

You know I can drill a well 10,000 feet down, then turn and go horizontal another 6,000 feet into a seam 100’ wide and stop my bit within 10’ of my target. I can build repair or even fix bikes online for people. My HVAC system I keep that dude on speed dial. Your the man Mike

Bugs are strangely attracted to contacts. I have found relays in RV gensets completely packed with tiny dead ants who crawled in one by one through a tiny vent hole..
Go figure!