Leak from under dash

I have a 2003 GMC Envoy and recently I noticed there is a water stain on the passenger side floor mat. I cannot tell if the leak occurs while the A/C is
running or if it happens after the vehicle is parked for a while. In any event, past experience tells me that it's the heater core. Is there any chance that it is another problem such as a clogged line somehere?
Thanks, Dennis
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likely that the drain hose for the condenser is clogged. You can find the hose coming out of the firewall on the passenger side below the blower motor housing. Rodding out the hose with a piece of coat hanger usually fixes it.
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Thanks Nicky, that was the problem exactly !!!!!
Dennis
wrote:

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