Remove the ECU mounted on the hump under the dash. Remove the steering column, remove the kick panels in front of each front door. There you will see a bolt on each side in a U bracket. Loosen these bolts 1/2 inch. Disconnect the radio antenna lead and the vacuum connector for the dash heater controls. Remove the 5 bolts at the front of the dash, where it meets the windshield. The dash will roll down to the the front seat. Have a friend help and lift the dash off the U brackets, and remove the dash. Under the hood on the right side, remove the ECM, drain the cooling system and discharge the A/C system. Disconnect the heater hoses and A/C line where they enter the fire wall. Remove the 3 nuts on the firewall. Back on the inside remove the 3 bolts securing the HVAC unit to the firewall. Remove the HVAC unit from the vehicle, and place on a work bench. Disassemble the HVAC unit and remove the heater core. Replace the core with a new one and reassemble. Takes about 4 hours for experienced tech. 10 hours for the novice.
GOOD LUCK
How do you change the heater core on a 1999 dodge ram 1500 pickup?
do as above
