Replace both positive and negative battery cables on a 1970 AMC Rebel Machine with 390ci V8 engine, restoring proper electrical connections between the battery, starter, and ground points.

Warnings

Tools required

Parts

• Positive battery cable assembly × 1 — Use OEM specification or equivalent with correct starter lug terminal
• Negative battery cable assembly × 1 — Use OEM specification or equivalent with engine block ground
• Battery terminal anti-corrosion washers × 2 — Felt or fiber washers

Preparation

1. Park vehicle on level ground and ensure transmission is in Park or Neutral with parking brake engaged
2. Turn off all electrical accessories and remove ignition key
3. Allow engine to cool completely if recently operated
4. Locate battery in engine compartment and inspect for obvious corrosion or damage
5. Take note of cable routing and attachment points before removal for proper installation

Procedure

1. 1

   Disconnect negative battery cable
   Using a 1/2 inch wrench, loosen the negative battery terminal bolt (marked with minus sign or black cable). Remove the cable from the battery post and position it away from the battery to prevent accidental contact. Ensure cable end cannot touch the terminal during the repair.
2. 2

   Disconnect positive battery cable
   Using a 1/2 inch wrench, loosen the positive battery terminal bolt (marked with plus sign or red cable). Remove the cable from the battery post. Cover the positive terminal with a clean rag to prevent accidental short circuits during the remaining work.
3. 3

   Remove negative cable ground connection
   Locate where the negative cable attaches to the engine block on the passenger side of the 390ci V8. Using a 13mm or 1/2 inch wrench, remove the bolt securing the negative cable ground terminal to the engine block. Note the location and any additional ground straps attached at this point.
4. 4

   Remove positive cable starter connection
   Access the starter motor on the passenger side of the engine. Locate the positive cable terminal connection on the starter solenoid. Using a 1/2 inch wrench, remove the nut securing the positive cable lug to the starter solenoid stud. Carefully remove the cable, noting the position of any additional wires on the same stud.
5. 5

   Remove old cables completely
   Trace both cables through the engine bay, removing any clips or fasteners securing them to the engine or frame. For the positive cable, check for any additional connection points such as the voltage regulator or ammeter if equipped. Remove cables completely from the vehicle.
6. 6

   Clean all connection points
   Using a wire brush, thoroughly clean the battery posts, starter solenoid stud, and engine block ground mounting point. Remove all corrosion, oxidation, and old cable debris. If battery terminals are heavily corroded, use a battery terminal cleaner tool to ensure a bright, clean surface. Clean the battery tray area if corrosion is present using baking soda and water solution.
7. 7

   Install new positive cable at starter
   Route the new positive cable from the battery location to the starter motor, following the original cable path. Connect the positive cable lug to the starter solenoid stud. Reinstall any additional wires that were present on this stud in their original positions. Install and tighten the nut securely using a 1/2 inch wrench, ensuring good metal-to-metal contact.
8. 8

   Install new negative cable at ground point
   Route the new negative cable from the battery location to the engine block ground point. Position the cable terminal and any additional ground straps at the mounting location. Install the ground bolt and tighten securely using a 13mm or 1/2 inch wrench, ensuring clean contact between the terminal and engine block mounting surface.
9. 9

   Secure cable routing
   Secure both new cables along their routing paths using original clips and fasteners, or new cable ties if originals are damaged. Ensure cables are routed away from sharp edges, hot exhaust components, and moving parts such as the fan and belts. Cables should have slight slack to prevent tension during engine movement.
10. 10

    Connect positive cable to battery
    Install an anti-corrosion washer on the positive battery post if using. Place the positive cable terminal onto the positive battery post, ensuring it seats fully. Using a 1/2 inch wrench, tighten the terminal bolt until snug and the terminal cannot be twisted by hand. Do not overtighten as this can damage the battery post.
11. 11

    Connect negative cable to battery
    Install an anti-corrosion washer on the negative battery post if using. Place the negative cable terminal onto the negative battery post, ensuring it seats fully. Using a 1/2 inch wrench, tighten the terminal bolt until snug and the terminal cannot be twisted by hand. Expect a small spark when making final connection - this is normal.

Reassembly

1. Apply a thin coat of dielectric grease or anti-corrosion spray to battery terminals after connection to prevent future corrosion
2. Verify all cable routing is clear of moving components and exhaust heat
3. Reset clock and radio presets as needed

Verification

• Attempt to start the engine - it should crank normally with good starter engagement
• Check that all electrical accessories function properly including lights, horn, and gauges
• Verify charging system is working by checking that battery voltage increases to 13.5-14.5 volts with engine running
• Inspect all connections for tightness - terminals should not move when moderate hand pressure is applied
• Look for any signs of heat discoloration or smoking at connections after running engine briefly, which would indicate poor connection

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