1995 Chrysler New Yorker AC control unit and blower on high

I recently came to own a beautiful 95 New Yorker with only 49000 miles on it. Everything is wonderful except the air conditioning.

Initially, the LED on the ac control unit would flash. I could touch the temperature knob and it would return to normal. After about 1000 miles, the LED went black completely, the fan went on full blast blowing hot air out.

I replaced the ac control unit with a salvage part. I read online to disconnect the battery to allow the computers to reset.

It seemed to work fine for about 30 minutes. The next time I started the car, I got the fan through the defroster. However the air was cool.

Now, if I disconnect the batter for a few minutes, when I start the car, the air blows through the front vents for 10 to 15 seconds before the vent door closes and the air is directed through the defroster.

When the first unit went out, the fault code shown was 66 which isn't on the list. Now, there is no fault code other than 12 due to disconnecting the battery.

This is a beautiful car. I really hope to get the air conditioner working reliably.

I am about to replace the body control unit with a salvage unit.

Any advise would be sincerely appreciated.