# Outside unit 24v signal wire disconnected, no voltage. Help!



## ysm79 (Sep 15, 2014)

Hi I bought an as is house but the outside unit does nothing when I turned on the AC. When I pushed the relay using a screw driver the condenser worked fine. I tested the signal wire white & red finding no voltage on them. I then went to the inside unit in the basement having found the signal wires going along with the bigger black insulated pipe was disconnected near the inside unit.

Question how can I fix this? Where should I hookup the 2 signal wires red & white on the inside unit (furnace, a coil, handler etc)? 

I am epa licensed & have all the tools needed as i do many houses. Still new to Hvac / elec repair

Should I test the thermalstate? But the 2 wires were cut near the furnace, it looked like to be connected to the inside unit before.

Also the inside unit looked much newer than the outside condenser. It could be cut off when the prev owner replaced a new inside unit.

Thank you very much for any advise!


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## MC 502 (Aug 14, 2013)

Check 24v power supply.


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## pfeifer (Oct 17, 2014)

What was disconnected? The wires or the insulated black pipe? If the pipe was I wouldn't worry about the wires. The wires go to the main board. Red to yellow/Y and white to common/C. Sounds like you know very little about HVAC and you may want to contact a pro. Because those wires didn't just fall off and were removed to keep your outside unit from coming on for some reason. Good luck!

Sent from my XT907 using Tapatalk


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## parralez (Oct 29, 2014)

*Chief Engineer*

The red wire and white wire that go out to the condenser unit are connected from the ignition module board.
The white wire is connected to the common of the 24 volts from the transformer or in the letter C on the board, and the red wire connected to the Y letter on the board.


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