Low air flow on MAX Cold vs. Normal A/C

[Paul T]

About 90 seconds after I move the AC switch to MAX Cold from Normal AC I experience a decrease in airflow from the system vents.
Has anyone out there had or fixed the same problem?
I assume the flapper door allowing coach air intake vs. outside air intake is not positioning properly but haven’t dug into the system previously. Any hints would be appreciated. Where exactly is that flapper door on a Suncruiser anyway?
Thanking you,

[Hikerdogs]

It's more likely that you're low on "freon" and the evaporator core is freezing up and restricting air flow. When set in the "normal" position the compressor cycles. If the system is low on freon it short cycles and doesn't cool well. When in the "Max AC" mode the compressor runs continuously. If the system is low on freon the evaporator (in the same compartment as the heater core) freezes over and restricts air flow into the passengers compartment.

[Mekanic]

look for a plastic shopping bag sucked up to the air inlet vent. sometimes the inlet is down over by the passenger side foot well.

[Paul T]

Hey, I like the plastic bag idea and will check it out today. The response going back to normal from max cold, (just about instantaneous), is much too fast for ice to melt and the cooling too good in normal for low Freon IMHO. Air flow slow to degrade going from normal to max cold but rapidly restored when normal reselected. Got to find that plastic bag I think.

[Mekanic]

On some vehicles the ONLY difference between max and norm is where the AC gets its air from.

[David Kanoy]

Paul T

I had the same problem; turned out to be a defective (rotted) vaccuum hose to the vaccuum motor that deflects the air from the defrost vents to the dash vents. Check your air flow to the defrost vents before and after you change from "Normal" to "Max". On my rig the air that would have normally been directed to the dash vents when on "Max" was going to the defrost vents instead. A short piece of vacuum hose fixed the problem.

Hope this helps.

David

[Hawkeye]

had the same problem, was a vacuum hose that came loose, Good Luck