farmer52 Posted May 17, 2009 Share Posted May 17, 2009 Ventilation air is not blowing from the RH center and RH vents in the VENT or A/C position. Air is blowing from the LH center and LH vents. In the DEFROST position there is air coming out the defroster vents on both the RH and LH sides. I have a HVAC book but it does not explain this issue. Are there separate vent tubes for the LH and RH sides? Do I need to remove the computer under the dash and circuit breaker panel to get access? I had the computer cover and dash panels off but cannot see where they connect. Any thoughts on this issue? Thanks! Quote Ken PRR Country and Charter member of the "Mack Pack" Link to comment https://www.bigmacktrucks.com/topic/9412-mh-hvac-air-flow-issues/ Share on other sites More sharing options...
Underdog Posted May 17, 2009 Share Posted May 17, 2009 Just have to do some good old fashioned "exploratory surgery". If only certain vents don't work the ducting may be apart or in your case there may be a potato roll stuck in there! From time to time the heater core may get plugged up with dust,etc. but in that case you would have no airflow anywhere. Quote Link to comment https://www.bigmacktrucks.com/topic/9412-mh-hvac-air-flow-issues/#findComment-35306 Share on other sites More sharing options...
Rob Posted May 17, 2009 Share Posted May 17, 2009 I don't know the layout of the HVAC in the newer stuff but sounds a bit like a problem in the ducting as suggested. There are modulating, and posioning motors in most newer stuff that could be bad. The problem could be a cable or mounting ear snapped on an actuating door in the airbox also. Most likely you will need to take things apart to inspect for damage.Rob Quote Plodding along with no job nor practical application for my existence, but still trying to fix what's broke. Link to comment https://www.bigmacktrucks.com/topic/9412-mh-hvac-air-flow-issues/#findComment-35315 Share on other sites More sharing options...
Underdog Posted May 17, 2009 Share Posted May 17, 2009 My CX came from the factory with a bent over pin on the wire connector for the fresh air door actuator. It was stuck on fresh air all the time for 5 years ! I always switch to "recirculate" when in dusty conditions. No wonder the cores were all plugged with dust. When I dug into my dash to solve my airflow problems, only then did I find the clogged cores and defective wiring. Quote Link to comment https://www.bigmacktrucks.com/topic/9412-mh-hvac-air-flow-issues/#findComment-35319 Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.