Central AC unit won't come on, needs re-wired

Heating, Ventilation, and Air Conditioning (HVAC)
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So… My central AC hasn’t worked since I moved in 5 years ago, and I never had the money to fix it. A dad from Cub Scouts said he’d fix it, and when he took a look at it said it would have to be totally re-wired. There are several sets of wires (probably dating back to when the house was built in 1950) running from the thermo to the furnace and to the AC unit. He hasn’t returned, and it’s been a month, so I want to do it myself.

I had someone check the unit a couple years ago, and it came on when he pushed a little switch inside it. He also checked the refrigerant pressure and said that looked good. So I’m assuming that the signal to turn on is getting lost somewhere. But where do I begin?

I’m cool with re-wiring everything, even the wires to the furnace. I downloaded a PDF of the thermostat manual, but I’d like some expert advice on how to go about this. I’m not a novice in repairs (mostly cars) and I do audio & video professionally, so I know my way around electricty, but I don’t even know how it’s all supposed to be run.

Any help, or links to helpful sites, would be most appreciated. Thermo is a White-Rodgers 1F80-51; AC is a York KA55HX45Y (though that might just be the fan model) and the furnace is a Janitrol, but I didn’t get the model number. Thanks!

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Lots of views, but no replies. Where’s the love?

Maybe I should be more specific. The thermo controls the heat just fine, so I feel confident the signal between the thermo and the furnace is OK. But the signal seems to get lost between the furnace and the AC unit outside. If I were to run a new wire between the evaporator/furnace and the AC unit, how would I do that?

There are a bunch of wires on the furnace, including some cloth-wrapped ones that look pretty darn old, and one newer-looking one that I can’t find the ends of. I also see two transformers, both wired.

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You probably am not getting any replies because no one can find any info on this model number.
Also since systems can vary greatly on how they are installed with the thermostat it is difficult to be very helpful.

All I can suggest is that you Google “central air conditioning repair help” with luck you may find a system hookup that is close to yours.

You may have to bite the bullet and get a pro in.

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[quote=denman;500668]
You may have to bite the bullet and get a pro in.[/quote]

He’s due in today, actually. Thanks anyway.