[gmachinz]

I have most of what I need to do it in my 86....basically a PWM module controls blower motor speed (and the stock motor is retained) and the main blend door PWM module reads off the ambient air temp sensor mounted in the front of the core support generally. If you select recirc (auto recirc if you select 60F) on the AC panel it pulls in cabin air only. I had a 1995 Buick Roadmaster wagon as a daily driver and the motorized climate control system was great!! The stepper motors install in place of the cable operated doors and PWM motors read off temp sensors to determine airflow. I've always wanted to do a swap in a truck....may just spend a weekend doing mine....we'll see-there never seems to be enough time lol