Hello all, hoping to get troubleshooting advice on a strange issue I’m having w/ my HVAC. Truck is a 2003 Dakota Quad Cab 4.7.
The issue I’m having is that only sometimes, the airflow out of the vents will be weak/nonexistent. Essentially, it feels like the HVAC gets “stuck” in a place where the air is coming out of none of the vents. I can hear the blower motor working hard, but no real airflow from vents in any position.
I have heard blower motor resistors can be troublesome; I’m wondering if anyone has experienced similar symptoms? I’m not confident about a specific component as the symptoms only appear intermittently. Maybe the solution is related to vehicle temp/engine vacuum because it seems to be only happening after the truck is already warm/has been driving for a few minutes?
I recently did head gaskets on the truck, so a misplaced vacuum line is a possibility. If there’s advice about a specific vacuum line that may be related to these symptoms I can double check connections etc. I don’t know if the HVAC issue existed before the hg repair job as I did not drive the truck before that.
Things I’ve observed:
The issue I’m having is that only sometimes, the airflow out of the vents will be weak/nonexistent. Essentially, it feels like the HVAC gets “stuck” in a place where the air is coming out of none of the vents. I can hear the blower motor working hard, but no real airflow from vents in any position.
I have heard blower motor resistors can be troublesome; I’m wondering if anyone has experienced similar symptoms? I’m not confident about a specific component as the symptoms only appear intermittently. Maybe the solution is related to vehicle temp/engine vacuum because it seems to be only happening after the truck is already warm/has been driving for a few minutes?
I recently did head gaskets on the truck, so a misplaced vacuum line is a possibility. If there’s advice about a specific vacuum line that may be related to these symptoms I can double check connections etc. I don’t know if the HVAC issue existed before the hg repair job as I did not drive the truck before that.
Things I’ve observed:
- A/C and Heat both work on the truck
- Seems to happen after the truck has been warmed up/started driving
- Sometimes, the HVAC works perfectly (airflow is strong, in all positions). Often I defrost my truck perfectly fine in the mornings with the heater blasting on full before driving
- After some driving, the airflow basically disappears. During this time, no real airflow can be felt from any position (defrost, dash, floor, etc). The blower motor still sounds like it’s blowing at the same strength as before, and it works on all 4 positions. But it feels like it’s blowing the air to nowhere as nothing is coming out of any vents.
