How to Remove a Heater Core From a 1997 Chevy Blazer

The Chevy Blazer is a mid-size SUV that is mechanically identical to the GMC Jimmy. It is designed to look and feel similar to Chevy's S-10 series of pickup trucks. The heater core regulates the warm air that is produced by the heater. If it malfunctions, the heater will not blow heat and very hot water could pour into the foot wells, causing injury. The heater core is located behind the dashboard on the passenger side. Removing the dash to access it takes an inexperienced mechanic two or three hours.

Things You'll Need

• Flat-head screwdriver
• Bucket
• Rubber hose plugs
• Phillips screwdriver
• Socket wrench
• Ratchet extension
• Flashlight

Instructions

1. Park the Blazer on a level surface and set the parking brake. Open the hood and disconnect the negative battery cable.

2. Disconnect the heater hoses from the engine firewall with a screwdriver. Place a bucket underneath the hoses to collect any coolant that spills. Insert plugs into the hose ends and hold them securely in place with the hose clamps.

3. Unscrew the screws in the bottom dash panels with a Phillips screwdriver. Pry up on the side of the panel and release the retaining clips. Remove the dash panels.

4. Remove the bolt at the base of each foot well with a socket wrench.

5. Lower the steering column to the lowest position. Remove the bolt below the center air vents with a socket wrench. Remove the left and right air vents by pulling them straight up, then remove the screws below with a Phillips screwdriver.

6. Grab the dashboard with two hands and pull it forward until the rear can be accessed. Disconnect all of the electrical connectors. Pull out on the dash and lift up at the same time, until the dash clears the steering wheel. Remove the dash from the Blazer.

7. Unplug the electrical connector from the heating module. Push on the vacuum connector quick-disconnect to remove it from the heating module. Remove the heating module mounting bolts. One of the bolts has to be accessed from the engine compartment. It will require a ratchet extension and flashlight to reach. Remove the heating module.

8. Remove the heater core retaining screws with a Phillips screwdriver. Remove the heater core.

References

• "Chevrolet S-10 and GMC Sonoma Pick-Ups,(1994 thru 2004) Chevrolet Blazer and GMC Jimmy,(1995 thru 2004) Oldsmobile Bravada and Isuzu Hombre, (1996 thru 2001)"; John Haynes; 2002