@

Showing posts with label dash vent and floor vents works properly. Show all posts
Showing posts with label dash vent and floor vents works properly. Show all posts

Monday, December 26, 2011

HVAC system blows hot/cold to dash and floor, but just does not blow through the defrost vents?

2003 Dodge Ram 1500 quad cab.

While replacing a leaking heater core (since the dash was removed anyway), a local mechanic attempted to correct a 2-year-old problem with my defrost: the selector switch does not direct air to the defrost vents. The system blows strong and hot/cold to dash and floor, but just does not blow through the defrost vents. He replaced/repaired the blend doors/housing/selector motor assemblies (blend door hinge pins and/or pin housing were broken/cracked). It seemed to work at least once after the repair. But after running through the selections on the HVAC switch (floor, dash, defrost) a couple of times, it again failed to blow to the defrost. During the second attempt to repair it, he first verified that the fixed/replaced blend door unit repairs/replacements had not broken again (they were still OK). He did realign/reattach the blend motor drive motors and reassembled the dash. I picked it up the 2nd time and had the same results...ran through the various settings a few times, got the defrost two blow once/twice, but soon the defrost failed to blow to the dash again.

At last the

Heater/blower switch was replaced and all is fine again.The problem solved after replacing the switch.Also the hose was pinched a bit.


@