Heater Core: Service and Repair

Fig. 17 Heater core & blower motor (less air conditioning). 88, 98 & Custom Cruiser:

Fig. 18 Heater core & blower motor (w/air conditioning). 88, 98 & Custom Cruiser:

88, 98 & CUSTOM CRUISER
Less A/C
1. Disconnect battery ground cable.
2. Disconnect blower resistor and blower motor wiring.
3. Drain cooling system into a suitable container, then remove heater hoses from heater core.
4. Remove seven screws attaching heater and blower case to plenum case, then remove case. The heater temperature air valve can be removed at this time by disconnecting valve cable and tapping hinge pin down until it clears the upper pivot, then lift valve and hinge pin out of lower pivot, Fig. 17.
5. Remove four screws securing heater core shroud, then shroud and core, Fig. 18.
6. Remove core mounting screws and clamps, then separate core from shroud.
7. Reverse procedure to install. Replace sealer as necessary during installation to prevent air and water leaks.

Fig. 18 Heater core & blower motor (w/air conditioning). 88, 98 & Custom Cruiser:

With A/C
1. Disconnect battery ground cable.
2. Disconnect blower resistor and blower motor wiring.
3. Disconnect A/C wiring, then heater core ground strap.
4. Remove thermostatic switch and diagnostic connector (if equipped).
5. Remove right half of hood seal, then seven screws attaching air inlet screen. Remove screen.
6. Remove five bolts attaching case to dash, nine upper to lower case attaching screws around flange and two upper to lower case attaching screws located inside plenum.
7. Remove upper case by lifting straight up, then off, Fig. 18.
8. Remove accumulator bracket, then lift evaporator out of case.
9. Remove heater hoses, then lift heater core out of case.
10. Reverse procedure to install. Replace sealer as necessary during installation to prevent air and water leaks.