Theory of Operation
WARNING: This page is about a different car, the 2011 RAM Cab & Chassis. However, it is still accessible from the selected car via links, so may be relevant.
The Powertrain Control Module (PCM) receives various information from the operator controls and A/C system to determine when the A/C Compressor Clutch should be turned on. The Totally Integrated Power Module (TIPM) receives a signal from the PCM to turn on the A/C Compressor Clutch. The TIPM supplies 12 Volts to the A/C Compressor Clutch which has a dedicated ground circuit. You will not receive a MIL lamp for this fault, but the customer may complain of poor A/C performance.