Battery

This procedure covers removal and replacement of the battery in a 1994-2007 Dodge Ram 2500 with the 5.9L Cummins diesel engine.

Warnings

Tools required

Parts

• Group 31 commercial battery (800+ CCA recommended for Cummins) × 1 — Use OEM specification or equivalent heavy-duty diesel battery
• Battery terminal protectors/washers × 2 — Anti-corrosion washers (optional)

Preparation

1. Ensure engine is off and key is removed from ignition
2. Open hood and secure with prop rod
3. Locate battery in engine compartment on driver side
4. Note radio security codes if applicable
5. If battery has corrosion, prepare baking soda solution for cleaning

Procedure

1. 1

   Disconnect negative battery cable
   Using a 10mm wrench, loosen the negative (-) battery terminal bolt. Do not fully remove the bolt, just loosen enough to slide the terminal off. Use a battery terminal puller if the terminal is stuck - do not pry with a screwdriver as this can damage the battery case or terminal.
2. 2

   Disconnect positive battery cable
   Using a 10mm wrench, loosen the positive (+) battery terminal bolt. Remove the terminal from the battery post. Keep the positive cable separated from any metal surfaces to prevent accidental shorts.
3. 3

   Remove battery hold-down bracket
   Locate the battery hold-down clamp (commonly a J-hook style clamp at the base of the battery on these trucks). Remove the hold-down fastener (verify socket size on your vehicle) and set the clamp aside.
4. 4

   Remove battery from tray
   Carefully lift the battery straight up and out of the battery tray. Each battery is heavy (approximately 40-55 lbs) - use proper lifting technique. Repeat for the second battery on the opposite side, noting the interconnect cable routing between the two batteries. Place old batteries on a stable surface away from the work area.
5. 5

   Clean battery tray and terminals
   Inspect the battery tray for corrosion or damage. Clean any corrosion from the tray using baking soda solution and a wire brush. Clean both battery cable terminals thoroughly with a wire brush or terminal cleaner to ensure good electrical contact. Rinse with water and dry completely.
6. 6

   Install new battery
   Place the new battery into the battery tray, orienting the terminals to match the original battery so the positive and negative cables reach their respective posts without strain. The battery should sit flush in the tray without rocking.
7. 7

   Install battery hold-down bracket
   Reinstall the battery hold-down (typically a J-hook clamp at the base of the battery on these trucks) and tighten the hold-down fastener snugly — do not over-torque, as excessive force can crack the battery case. Verify the battery does not rock or shift.
   Torque spec

   Battery Hold-Down Bolt8 Nm (6 lb-ft)
8. 8

   Connect positive battery cable
   Place the positive (+) cable terminal onto the positive battery post. Ensure the terminal is fully seated on the post. Apply dielectric grease to the connection if desired. Tighten the terminal bolt to specification - do not overtighten as this can crack the terminal.
   Torque spec

   Battery Terminal Bolts6 Nm (4 lb-ft)
9. 9

   Connect negative battery cable
   Place the negative (-) cable terminal onto the negative battery post. Ensure the terminal is fully seated on the post. Apply dielectric grease to the connection if desired. Tighten the terminal bolt to specification - do not overtighten as this can crack the terminal.
   Torque spec

   Battery Terminal Bolts6 Nm (4 lb-ft)

Reassembly

1. Double-check that both battery terminals are tight and secure
2. Verify hold-down bracket is properly torqued and battery does not move
3. Apply battery terminal protector spray or grease to prevent corrosion

Verification

• Turn key to ON position (do not start) and verify dash lights illuminate
• Start the engine and verify it cranks normally
• Check that all electrical accessories function properly (lights, radio, windows)
• Verify no warning lights remain on the dash after startup
• Inspect terminals for proper connection and no signs of arcing or sparking
• Reset clock and radio presets as needed

Related trouble codes on this vehicle

Codes that commonly send this job to the bay — tap one for symptoms, causes, and diagnostic steps.

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