Alternator, Battery, and Starter Connections Check

49X mm 15.01.001
    Warning: Batteries generate explosive gas as a by-product of their chemical process. Do not smoke when working around batteries. Put out all flames and remove any source of sparks or intense heat in the vicinity of the battery compartment. Make sure the battery compartment has been completely vented before disconnecting or connecting the battery cables.

    Battery acid is extremely harmful if splashed in the eyes or on the skin. Always wear a face shield and protective clothing when working around batteries.

  1. Park the vehicle on a level surface, shut down the engine, and set the parking brake. Chock the tires.
  2. Disconnect the batteries. Remove the negative cables first, and then the positive cables.
  3. Check the tightness of the alternator bracket fasteners; tighten the fasteners as needed. For torque values, see of the Western Star 47X and 49X Workshop Manual.
  4. Check that all electrical connections at the alternator and starter are clean. Clean and tighten all charging system electrical connections, including the connections at the starter B terminal and ground terminal, and where the alternator charging cable terminates. Connections should be free of corrosion, dirt and moisture. Connections should not have signs of thermal distortion, warping, discoloration, high amperage heating or discoloring. If needed, disconnect cables, scrub and clean using a nylon brush. Clean debris with vacuum or electrical contact cleaner such as CRC QD® Electronic Cleaner. Inspect terminals and mating contact terminal plating. If the terminal plating exhibits signs of unrecoverable corrosion, the component and terminal will need to be replaced. Indications of unrecoverable corrosion on terminal plating are:

    • heavy staining that cannot be cleaned off with nylon brush or contact cleaner;

    • erosion and pitting on terminal plating causing uneven surfaces; or

    • discoloration caused by outer layer of plating being removed by corrosion or wear, exposing the under layer material of terminal.

  5. Inspect the battery cables for wear, and replace them if they are damaged. Clean the cable connector terminals with a wire brush. See  of the Western Star 47X and 49X Workshop Manual for adjustment, repair, or replacement instructions.
    1. Clean and tighten the battery ground cable, terminal, and clamps.
    2. Inspect the retainer assembly or battery hold-downs, and the battery box. Replace worn or damaged parts. Remove any corrosion with a wire brush, and wash with a weak solution of baking soda and water. Flush with clean water, and dry. Paint the retainer assembly if needed, to prevent rusting.
    3. Check that foreign objects, such as stones, bolts, and nuts, are removed from the battery box.
    4. After cleaning, connect the cables to the batteries and tighten them to the torque specifications listed on the battery, generally 10 to 15 lbf·ft (14 to 20 N·m).
    5. Coat the battery terminals with dielectric grease.
  6. Check the alternator wiring for missing insulation, kinks, and heat damage. Replace or repair as needed.
  7. Check the terminals on the battery shut-off switch and the magnetic switch. Make sure the terminal connections are clean and tight. Coat the terminal connections with dielectric red enamel after cleaning.
Note:
Parent topic: Alternators and Starters
Document Number: 0000118177
Manual Publication Date: 2024-05-16
Topic Publication Date: 2024-10-31