2ND GEN RAM1500 NO HOT AIR BLOWI

[Ramgirl96]

Hey guys, I just bought a 96 ram 5.9 with possible cracked heads due to overheating. I know very little about the history of the truck. Before I take it to have the engine rebuilt I am going through and fixing small things that will not be covered in the rebuild. One problem I’m having is that it takes a long time for the truck to overheat at idle and NO HOT AIR will come out of the vents. Air does comes though but it’s outside temp. I’ve flushed the heater core and no visible water on floor board if the core was bad. Unfortunately the previous owner did an exhaust bypass and the only codes it is throwing are for the oxygen sensors. Possibly the thermostat or even the heater flaps.. Anybody else have this issue with their truck before? I appreciate any advice! Thank you!

 

[RodeoRam]

The 2nd Gens are notorious for clogged cores and broken actuators on the fresh air and blend doors in the HVAC system. If both heater hoses are hot when the engine is at operating temp, then it shouldn't be your core, although both could be hot if the core is partially clogged. Mine was partially clogged and only around 40 degree air was blowing out. It didn't help that it was -11 degrees outside.

Search YouTube for Dodge HVAC door actuator repair. There was one on 3rd Gens that I watched months ago that might help. Of course, it was 10 years too late to save me some money.

 

[Mop]

See above. The blend door actuator has a plastic hinge that crumbles over time. Take it down, if it's bad, buy a Heater Treater. Follow directions, and it's done.
If it's the vent doors, it could be a simple vacuum leak, and they aren't closing completely. Buy 3mm rubber tubing. Bypass the factory plastic lines. Done.