'99 Suburban A/C fan problem

[1999suburban]

I'm off on a family road trip tomorrow so this is bad timing. After an hour or so, my front A/C fan pressure dies. It feels cold coming out of the vents, but with hardly any pressure behind it. I also notice significant dripping on the passenger side carpet. If I turn off the vehicle for 1/2 hour, normal pressure returns. The rear A/C pressure is fine. I've taken it to a local mechanic, but he couldn't find anything wrong. Help!!!runaround

[Eubie]

Not Suburban specific because I don't work on any except mine, but if an evaporator ices up you will get this symptom. Evaps are supposed to stay above 32F to prevent this. The control unit is supposed to cut out the compressor clutch at certain times and if it is allowing the compressor to run too much you might have an evaporator freeze.

A possible check would be to drive it until it loses air flow then park it. If you don't see condensate dripping out pretty much right away, look for it to start coming out in a few minutes. This would strongly suggest evap icing.

Others with Suburban-specific experience might have some other suggestions.

[mxmikie]

change your cabin air filter and clean out the evap drain