How to Replace the Heater Core in a 1997 Pontiac Grand Am

If you are losing engine coolant in your 1997 Pontiac Grand Am, and you don't see any obvious leaking, check the floor in your car. If it is wet, then your heater core is shot and you need to replace it. You might also have a clogged heater core. In either case, you will not have any heat inside the car. The worst-case scenario is that your Grand Am is overheating. Continuous overheating creates other, more expensive repairs, so you need to replace the heater core as soon as possible.

Instructions

Open the engine compartment and disconnect the negative battery using a wrench to loosen the terminal nut. Place the drain pan under the radiator and open the valve with a wrench to drain the engine coolant. Place the engine coolant out of reach of household pets until you are able to recycle it.

Raise the front of the Grand Am with the automobile jack. Place a jack stand under the car near the jacking point and raise it to the frame. Crawl under the car and detach the drain tube from the heater core. Disconnect the heater hoses from the heater core using a screwdriver to loosen the hose clamps.

Remove the jack stand from under the Grand Am and lower the vehicle to the ground. Inside the vehicle, remove the right and left sound insulators from the dash panel. Remove the trim plate from the steering column using a screwdriver. Remove the trim plate from the instrument cluster with the screwdriver.

Remove the glove compartment using the screwdriver. Remove the extension plate from the instrument panel with the screwdriver. Remove the radio from the dash. Unplug the wiring harness and the antenna cable. Disconnect the climate control unit and remove it. Remove the two nuts between the instrument panel and the cowl with a wrench.

Remove the screws attaching the panel and then unplug the wiring harnesses in the glove box. Under the hood, disconnect the bulkhead connector between the wiper motor and the left fender. Move back to the inside of the car and remove the nuts that connect the steering column harness to the cowl, using a wrench.

Remove the support bolts from the steering column with a wrench. Disconnect the high-beam dimmer switch, the ignition switch, the turn signal switch, the cruise control and the start switch electrical connectors. Remove the defroster grilles. Unfasten the screws along the pad that connect the pad to the cowl with the screwdriver.

Remove the pad brace screw inside the glove compartment opening with a screwdriver. Remove the pad from the instrument panel. Disconnect the antenna lead from the pad, then disconnect the hoses from the defroster. Unplug the body electrical lead from the right side of the instrument panel.

Remove the heater core access cover using a wrench. Remove the heater core mounting bolts using a wrench and pull it out of the vehicle.

Place the new heater core in the car and mount it using a wrench. Replace the cover on the heater core box and tighten the bolts with a wrench. Plug in the body electrical lead on the right side of the instrument panel. Connect the defroster hoses and tighten the clamps with a screwdriver. Connect the antenna lead to the dash pad.

Install the pad on the instrument panel and install the pad brace and screw with the screwdriver. Install the screws and secure the pad to the cowl using a screwdriver. Install the defroster grilles. Connect the wiring harness for the high beams, the ignition switch, the turn signals, the cruise control and the start switch clutch.

Reinstall the nuts that secure the steering column harness to the cowl, using a wrench. Move to the engine compartment and connect the bulkhead connector between the wiper motor and the left fender. Move back to the inside of the car and reinstall the screws that attach the panel, using the screwdriver. Plug the wiring harness together at the glove box.

Reinstall the nuts that attach the panel to the cowl using a wrench. Install the climate control panel and connect the wiring harness. Plug the electrical wire and antenna cable into the radio. Reinstall the radio in the dash and secure it with the screwdriver. Reinstall the trim extension plate to the dash panel with the screwdriver.

Reinstall the glove box using a screwdriver. Install the instrument cluster and trim panel using a screwdriver. Reattach the cover on the steering column and tighten the screws with the screwdriver. Reinstall the sound insulators under the dash. Clean any liquid that may have gotten inside the car, using the rags.

Move to the outside of the Grand Am and raise it with the automobile jack. Place a jack stand under the car near the jacking point and raise it to the frame. Crawl under the car and connect the heater hoses to the heater core. Tighten the hose clamps with the screwdriver. Connect the drain tube to the heater core. Remove the jack stand from under the car.

Lower the Grand Am to the ground. Make sure the valve on the bottom of the radiator is closed. Connect the negative battery cable and tighten the terminal nut with a wrench. Refill the radiator and reservoir with fresh engine coolant. Start the Grand Am and check thoroughly for leaking.