Trying to hunt down a malfunctioning HVAC head (no A/C) and cooling fans come on upon cold start. Got a reconditioned AC head unit from Marc Anderson and after disconnecting the battery, I installed it. Radio installers had not connected the AC button (problem 1 fixed). Easy. Before buttoning it all up, I reconnected the battery. Turned the key and the AC fans did not come on, that's good. Fans didn't work, they did with the old head unit. Started the car, no AC, no fans.