Heater Core: Service and Repair

Less Air Conditioning

Fig. 11 Heater core replacement. E-100---350 less air conditioning:

1. Disconnect battery ground cable. On models equipped with dual batteries, disconnect both negative cables. Remove RH battery from vehicle.
2. Drain cooling system.
3. Disconnect resistor electrical connector, then the blower motor lead wire from wiring harness.
4. Remove ground wire attaching screw from dash.
5. Disconnect hoses from heater core, then remove plastic wrap securing hoses to heater assembly.
6. Remove 5 heater assembly attaching screws from passenger compartment, then lift heater assembly out of engine compartment.
7. Remove seal and retainer from front of heater core case, then slide core and seal out of case.
8. Reverse procedure to install.






W/Air Conditioning

Fig. 12 Heater core replacement. E-100---350 w/air conditioning:

1. Disconnect battery ground cable. On models equipped with dual batteries, disconnect both negative cables. Remove RH battery from vehicle.
2. Disconnect electrical connector from resistor on front of air conditioner blower scroll cover.
3. Disconnect vacuum hose from outside recirculated door vacuum motor.
4. Remove air conditioner blower cover attaching screws and the cover.
5. Remove outside-recirculated door shaft push nut and washer.
6. Remove control cable attaching screw and slide cable over bracket.
7. Remove cable clip or wire loop from blend door shaft.
8. Remove 9 air conditioner blower motor housing attaching screws and the housing.
9. Remove 3 blend door housing attaching screws and the housing.
10. Drain cooling system, then disconnect hoses from heater core.
11. Remove 2 heater core retaining bracket attaching screws and the bracket.
12. Remove heater core and seal assembly.
13. Reverse procedure to install.