Ok I have an interesting problem. My 90 xj has been under water a few times and I think I have some silt or dirt in the fins on the heater core. The blower works fine when its on the cold air side (no a/c) but when I put it on heat it moves maybe 50% of the air. Anyone know a way to clean out the core and or ducts without removing the heater core?

 

rtemove the blower motor resistor spray in hole with water hose put plactic container in fioor board to catch excees water that does not drain from drip hose