HVAC Air Flow Switching to Defrost When Accelerating on Dodge Ram Wagon 2500

The AC/heater (HVAC) system may unexpectedly switch to the defrost mode when accelerating. This system is operated by engine vacuum and should be inspected for any vacuum leaks if this problem develops.  There is also a revised vacuum check valve available to address this concern.

RepairPal Verified
Average mileage: 280,000 (280,000–280,000)
8 model years affected: 1995, 1996, 1997, 1998, more1999, 2000, 2001, 2002
9 people reported this problem
0 people shared problem details
Related Items:
The fuse may blow repeatedly for the HVAC blower motor or the motor may stop working all togeth...
The HVAC blower may operate on high speed only. This is commonly caused by a failed blower moto...
Some vehicles may exhibit a "buzz", whining", or "moaning" like noise from the transmission whe...
When idealing sometimes it will stall and sometimes it wont.

Related Content