A/C won't shut off

[redtail]

Have two A/C units one primary come on, and the second one come either by lower the temp or if the first unit is not maintaining the temp in the house. Also, I can switch the the units so either one can be the primary. With that said, I try raise the temp gauge to the primary unit would shut off, and it Didn't. I try using switch to shut off the unit and it didn't. So next step switch the second unit to be the primary, and shut off the circuit breaker on the first unit, and everything is working.

I am guessing that the relay in the first unit not working. My question the relay something I can replace? Not sure where it is on the A/C unit. I don't remember what brand it is at the moment. I will go out and look in the morning.

Thanks 

[redtail]

Model Goodman CM36-1E (B OR can't read the last digit.

[JWWebster]

You sayin the outside unit stays on or the whole unit stays on when you turn it off?

[redtail]

The whole unit is running. (fan, compresser, etc)

[JWWebster]

Must be in the thermostat. Does the unit run with the thermostat disconnected? That could be a relay on the board.

[redtail]

The other unit works like normal. When the temp in the house is reach it shut off.

[JWWebster]

Take some photos of the unit, we can't look up goodman online

[redtail]

here are few pictures

[JWWebster]

To the right of the capacitors is what they call a contactor. If the contactors points are fried together the only way to turn the unit off is by turning the breaker off.
I do not recommend a novice replacing this one. You better get a guy out there to look at it.
A new contactor won't even look that one.

[jumptrout51]

No biggie,replace the contactor. Sooner or later all contactors go out or get stuck or get ants in them and won't conduct.

[jumptrout51]

Repair your wires terminal ends,they look bad.
When replacing the contactor keep like colored wires on the same side. Reds with red,Blacks with black etc.

[redtail]

I spray some contact cleaner, and it help it. So I know I in the right area. Of it still need to be replace.

If I turn off the circuit breaker, and I know high voltage is coming into to it. I was going to use muti-meter to check voltages before I start taking it part. What else should I becareful of be for removing it?

jumptrout51

I notice the wiring issue too. I had plan repairing the connection, once I replace the part.

Thanks

[jumptrout51]

Since it is sticking replace it.
The contact points are worn that causes voltage and amperage issues that affect the compressor and fan motor.
Loose terminal ends and bad contactors cause the wire stress you are seeing.

[Icehouse]

  The condenser coils need a good cleaning. Also cover the electrical box. 

[dave@orion]

Icehouse.....spot on mate..at times the simplest things are overseen. while replacing the contactor  it's also important to look out for probable causes for the error. a chocked condenser could make the compressor draw more current heating up and arking contact points eventually.