New control wire?

[homersapian]

I had a rat get into my house a month or so ago, and I've since killed the rat, but he left me a surprise to find as it warmed up!

My heat has been working just fine, but I switched over to ac today and noticed the fan was blowing, but it wasn't cooling down. The compressor wasn't on outside. I looked at the control wire coming from the furnace and the rat chewed the insulation off of all 5 wires for about a inch of the wire. I tried wrapping them each in electrical tape just to get it going until I can run a new wire this weekend, but that didn't work either.

I'm assuming that there is another short somewhere in the control wire (about 50ft to furnace under the house), but is there something else I need reset other than the main board inside?

 

[Dehno]

Did you check the breaker for the outdoor unit?

 

[homersapian]

I did, I don't have any breakers thrown...

 

[Dehno]

There shouldn't be anything else to reset as far as the unit goes. I'm guessing there's probably more chewing somewhere down the wires.

The fan that comes on is the blower right? Nothing comes on outside?

 

[bazar01]

I did, I don't have any breakers thrown...

Do you have a heat pump or straight cool and electric heat unit?
The unit type will determine how many wires on the control cable are used from the furnace to the outside condenser unit.
Then you can check wire continuity from the furnace. Just make sure the unit it off so you don't burn up the transformer.

 

[homersapian]

The inside blower is coming on, but nothing on the outside unit turns on.

I just have straight cool and gas heat. On the board inside, it looks like i just have 2 wires being used going to the outside unit.

I'll pull the outside breaker and check continuity when the rain stops tomorrow...

I hate vermin!

 

[bazar01]

Straight cool should be easy. Two wires from furnace to outside unit wired to compressor and fan contactor control coil.
Make sure you turn off both the inside and outside unit breakers so you don't burn up the transformer.
Can you still get a good section of the cable past the area chewed up then just pull the thermostat wire to get it closer to the furnace termination? Or just splice a short cable to the existing one if its a challenge to pull a new cable through the wall.
Good luck.

 

[Random Guy]

If you end up having to run a new cable all the way to the outdoor unit, I'd recommend pulling 4 or 5 wire cable. It'll mean that you don't have to run a new wire down the road if you replace the unit with one that needs more than two wires.

 

[Dehno]

Did you ever get this figured
Out?