I have noticed that after the truck sits in the rain, there will be water on the floormat underneath the heater box right where the blower motor is. It is NOT coolant. The water has to be coming from the air intake for the ventilation system? There is a drain hose on the firewall side right where the heater hoses go in, but this is not plugged. The water only comes out when the fan is on. So I am assuming that it is pooling in the fan housing. Drain or not, I know it shouldn't be getting in there. The only thing I can think of is taking apart the grill that covers the wiper mechanism between the hood and the windshield as that is where the air is drawn in from.

I am just wondering if anyone else has had this problem on a '98 Z71, and if/how it was fixed?

Any suggestions?
Thanks.

 

the drain by the heater hoses is for the A/C condensation..........pull the wiper cowl off and see if you see anything obvious..........use a hose to help you find the leak...pull the blower motor and run a hose over the windshield while you look where the blower was (make sure you have a second set of hands to shut the hose off) also check the assembly under the hood where the a/c and heater core are for holes or obvious places where it might leak