I made a "dyno" to test your HVAC control on the dash. vacuum pumps blend dors etc. If your not sure if it is broken and I can test it for you and possibly rebuilt your 9 port switch if it isn't working. Not looking to make money just looking to help. if my pm is full email me a, and if you have some units laying around, and you would like to send them to me to test or use for parts to help other guys, most of GM part numbers for these are gone or hug money If it tests well I will mail it back for shipping costs only

Tom DeMarco