nothing works!

[tsergang]

About 3 weeks ago, we decided that our a/c condenser and "A" coil could use a good cleaning. Furnace model number is MGHA-056ABFC-01 (Nordyne) The furnace had not been run for a few weeks prior to that, as weather did not call for it. Anyway, we cleaned everything up, put it back together and turned the switch on the thermostat over to "cool". It took a few minutes, but eventually, it did kick on and start to cool. Like idiots, we turned the thermostat to the off position later that evening because we had a programmable T-stat and did not know how to program a new "cooling" program. We figured that we would work on it the next day. So... the next afternoon, we go to turn it back over to cool and nothing happens. No matter what we have done since then, nothing happens. There is power everywhere, we have replaced the T-stat, the fan and the limit switches and also the relay that all of the t-stat wires plug into. most wiring has also been replaced. If we turn the blower to the manual position on the blower switch(whitch we also replaced) the fan will work. The A/C nor the heat will kick on though. If we leave the blower switch in the "on" for auto position, nothing happens. We can also ground out the a/c condenser t-stat wire and that will make the outside condenser kick on. Everything worked perfectly until we cleaned it and we are all out of ideas. Please help!!

[Robert]

Hi,

Look closely at the wiring diagram and retrace the wires to be sure all are correct and tightly connected.


Sounds like a miswire somewhere with all the parts replacing and wiring replacements.



Thanks,
Robert

[tsergang]

That's kind of what we figured too. We are out of town at the moment but will retrace everything when we get home and let you know. Thanks for the reply and also for the wonderfully fast shipping of your replacement parts!

[Robert]

Hi,

You're very welcome, we're happy to help.



Thanks,
Robert

[tsergang]

We have went through all of the wiring, it is wired correctly. There is, however, no power to the fan switch in the auto position from the on/off switch. It does not seem to matter what we do, we just cannot get power to that switch. Any ideas?

[Robert]

Hi,


How many wires are connected to your t-stat ?


Thanks,
Robert

[tsergang]

We have a 4 wire but last night did find that the transformer was blown. That has since been fixed and now everything inside turns on and off like it should. Now though, the condensor unit outside, is the problem. The fan om the unit will turn on but the actual compressor will not. It makes a sound like it wants to kick on but nothing happens. This unit worked just fine all summer long the year before. What could have gone wrong???

[Robert]

Bad run capacitor possibly.


Thanks,
Robert

[tsergang]

Hi Robert, We've replaced the run capacitor as of today and still the same problem. Just seems that we have bad luck this season. Any other ideas?
Thanks, Sarah

[Robert]

Hi,

Need to see if the voltage needed from the two wires from contactor to compressor is getting the 240VAC to compressor.

If so and run cap is new/good and wired correctly, then let it sit overnight OFF and try again when it is cooled off.


If it still does it, need to call an hvac tech out to test compressor. May need a start assist kit added.


Thanks,
Robert