We recently had the heater core replaced in our 2000 Jeep grand Cherokee limited, we vacuumed all the coolant from the passenger floor, but there still seems to be coolant puddle on passenger floorboards?!!!
Check for loose hose connection by the firewall
If it is coolant then the core is still bad, either it was damaged during the install or was bad right out of the box, that is why I have always tested new cores before installing them, and yes I have had them be bad, usually a ratio of 1 bad in 5 good ones. You should also check the A/C drain as it should be coming out of there too. It might be plugged.
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