Dodge Truck - No A/C (and other problems...)

2006 and later Dodge Trucks have a Totally Integrated Power Module, TIPM. This module is used instead of a fuse box, and there is no relay controlling the A/C as in previous generations. This TIPM has been very problematic for Dodge, particularly with the 5.9 Diesel trucks. The TIPM controls not only the air conditioning, but also brakes, lights, and various other items. There are several flashes and updates available from the dealer for this module. If the vehicle is experiencing erratic or no A/C clutch engagement, it is necessary to examine the TIPM. Keep in mind, the clutch coil on this compressor has an embedded diode which also commonly fails, many times in conjunction with the TIPM, so don't forget to test resistance.