A/C problems: no compressor- fan works.

System info first: York 13S AC unit, installed last year around this time, fan runs fine, compressor won't start.

So I have checked the cap. It's fine. Even ordered a replacement and got the same issue. I have unplugged the fan so I can hear the compressor. It tries to start for about 1-2 seconds. Goes quiet for say 30 seconds and then tries to start again.

I haven't ruled out the contactor, but I'm assuming that since I have power for the fan that it's fine (and it's like a year old).

Would the compressor have a switch on it that's tripped preventing start? The compressor is right in the center of the unit.

Also any tips for getting the fan out of the way easily to access the compressor? All the how-to replace the compressor videos don't show anything about removing the fan.

Also, the unit is under warranty, but only for parts. So I'd like to avoid a service call of $100 or more just to be told that this cheap easy fix or that switch was tripped.

 

That does not appear to be a complete model #, can you post a wiring Dia? It could be a low pressure switch opening the circuit.does the fan cycle off every 1to 2 seconds?

 

When you say the fan runs fine, I assume you're referring to the condenser fan (outside unit) and not the air handler fan (blower). Many systems have a low pressure switch which is wired in series with the contactor control voltage. The low pressure switch prevents the compressor from starting if the system is dangerously low on refrigerant. However, if the low pressure switch 'tripped", it would prevent the contactor from closing, and the condenser fan wouldn't come on, so it's likely not that.

As for the contactor being the problem, it's unlikely. However, if the contactor is a double pole unit and the condenser fan is a 120V motor (only using one side of the 240V power), it would be possible if one pole wasn't making electrical contact (burned contacts). If you have a voltmeter (multimeter), with the thermostat calling for cooling, very carefully check the voltage across the top terminals and then across the bottom terminals (I don't know which pair is the input and which is output). If you have ~240VAC between both pairs of terminals (top pair and bottom pair), then the contactor is working.

 

I would put on some safety glasses and check for a melted wire connector at the compressor terminals (after removing power).

 

You've got a year parts and labor...... is it under that ?
I don't see a basic repair there.

 

The labor warranty has expired. Not too long ago too, like earlier this year.

MODEL# YCJD42S41S2

The fan does not cycle off. It stays constant. Yes, the condenser fan.

I'll check the compressor wiring soon. It's not that easy to get to since the compressor is in the middle of the unit.

I will see if the unit panel has the wiring diagram and snap a picture.

 

Update for today. Bought a new contactor locally just to make sure that wasn't it. It wasn't old and new still work fine after testing. I took the HP switch out of the loop by just splicing the wires to see if that's what it was. Nope. Still the same result.

I turned off the power to the air handler to reset it (new computer controlled York air handler). Nothing.

I beat on the compressor with a hammer. Nothing.

At this point I think I'm just going to have to put in a service call.

The compressor was hot after letting it sit there trying to start for several minutes.

Has anyone heard of compressor failure at such low hours? It's probably only ran for like 6 months. We have gas heat so it only gets use in the summer months.

 

Odd at 6 months to fail,but it can happen,was it ever run in cooler temps, is there a crankcase heater on it,if refrigerant should get back into the oil it can cause the compressor to seize up.

 

No. Typically I leave it off until absolutely have to turn it on. Which is usually once it starts hitting mid 70's.