Question about 1988 GMC S-15

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How to replace heater core on 89 s15

Exactly where do i start

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Disconnect negative battery cable
remove coolant reservoir
dis-connect heater hoses at heater core
remove mounting screws and nuts from the heater housing in the engine compartment
remove glove box door and liner
disconnect heater controls ( be sure to lable them so you know where to put them later )
disconnect the computer ( ECM ) an mounting bracket
remove the radio antenna cable
remove the kick pannel and detech the right lower corner of the dash pannel.
pull the heater assembly to the rear for access and dis-connect the wiring harness
remove the screws and nuts retaining the heater housing inside the cab
remove the heater housing from the vehicle
detach the core retaining straps
and wala you got it
to install it just reverse these steps.
good luck

Posted on Oct 10, 2008


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