1998 5.2 Durango SLT
The heat doesn't come out of the vents/defroster/floor with as much pressure when the temperature dial is on hot compared to cold. It's at least half the pressure. The fan sounds like it's blowing the same, but the pressure is much less. Any ideas what would cause this or how to fix it?

Thanks,
Jeff.

 

Sounds like you have a bad diaphragm or a vacuum leak. I'm thinking vacuum leak.[>:]

 

Thanks for the reply.

I don't know much about vacuum leaks. Researched a little and it seems like they're possibly hard to locate. Did I understand that correctly? It could be caused by something as simple as the faulty PCV or as complicated as the plenum pan gasket? Is the only way to test for a vacuum leak with a gauge or is the another way?

FYI: The check engine light is not on. 108,000 miles.

 

Check the engine side of the firewall, drivers side. There's a small hard hose that comes from the firewall that is attached to a vacuum hose. Check that, mine broke. Also do a search for "heater" and/or "blower" and you may find a couple of great threads.