Here's a general outline of the steps involved:
1. Preparation:
* Safety First: Disconnect the negative battery cable. Wear safety glasses and gloves.
* Gather Tools: You'll need various sockets, wrenches, screwdrivers, pliers, a coolant recovery system, a drain pan, a new heater core, new o-rings, and potentially a pressure tester for the cooling system. A shop manual is essential.
* Drain Coolant: Completely drain the engine coolant. Locate the drain plug(s) on the radiator and engine block.
* Gather Materials: Have plenty of clean rags and paper towels on hand. New coolant will also be needed.
2. Accessing the Heater Core:
* Dashboard Removal (Most Likely): This is the most challenging part. You'll likely need to partially or completely remove the dashboard to access the heater core. This involves removing many components, including the steering column, radio, HVAC controls, and various trim pieces. This is where a repair manual is crucial. Take photos as you disassemble parts to help with reassembly.
* Alternative Access (Possibly): Some models *might* allow access through the firewall, but this is less common and often more difficult.
3. Heater Core Removal and Replacement:
* Disconnect Hoses: Carefully disconnect the heater core hoses. Be prepared for some coolant spillage.
* Remove the Heater Core: Once the hoses are disconnected, carefully remove the heater core from its housing. This often involves removing mounting bolts or clips.
* Install New Heater Core: Install the new heater core, ensuring the o-rings are properly seated.
* Reconnect Hoses: Reconnect the heater hoses securely, making sure there are no leaks.
4. Reassembly:
* Reinstall Dashboard: Carefully reinstall all the dashboard components in reverse order of removal. This is a meticulous process.
* Refill Coolant: Refill the cooling system with the correct type and amount of coolant.
* Bleed the System: Bleed the air from the cooling system to prevent overheating. This usually involves opening bleed valves on the engine and radiator.
* Test: Run the engine and check for leaks. Observe the heater function. Use a pressure tester to check for leaks in the cooling system.
Important Considerations:
* Bleeding the System: Improperly bleeding the cooling system can lead to overheating.
* Coolant Type: Use the correct type of coolant specified for your vehicle.
* Professional Help: If you're not comfortable with complex automotive repairs, it's strongly recommended to take your vehicle to a qualified mechanic. The cost of a professional repair might be less than the cost of damaging components during a DIY attempt.
This is a highly simplified overview. The actual process is significantly more complex and requires patience, attention to detail, and the proper tools. A repair manual specific to your 2000 Dodge Ram diesel is absolutely essential. Without it, you risk causing further damage to your vehicle. Consider the complexity and your mechanical skills before attempting this repair yourself.
