How to Repair Battery Cables in a Car

Over time, the cables to your vehicle's battery corrode. Unreliable connections to the starter system may be the result of this corrosion. Maintaining the power system of your electrical components should be a priority to keep everything working on the vehicle. When the battery corrosion builds up enough that it begins to eat away at the cables, you need to take the time to clean it up.

Difficulty: Moderately Easy

Instructions

1. Remove the battery cables from the battery posts. Always remove the positive terminal first and then the negative terminal. Removing the negative cable first creates a situation where the positive cable could spark or weld itself to another metal piece of the engine. You should use gloves and goggles during this procedure to avoid the hazard of the very dangerous dried battery acid.

2. Use a battery post cleaner and clean the battery post until it is shiny. While the cables are disconnected, clean the battery cable ends also. The other end of the post cleaner has a wire brush to clean the inside surface to a shiny gleam.

3. Coat the inside surface and outer surface of the post and cable with a thin layer of petroleum jelly. The petroleum jelly will form thin protective coating on the metal parts to prevent further corrosion. To further prevent corrosion, install a pair of felt type washers on the battery posts. These washers you can find at Wal-Mart or any automotive supply store.

4. Examine the cables themselves and determine if they need repair or replacement. Cables for some cars can cost a lot. This is why keeping an eye on them during routine maintenance is so important. If the clamp on the end of one or both of the cables has corroded, you need to repair the cable or replace it.

5. Cut the remaining wires that hold the cable and clamp together. Discard the old clamp and clean up the end of the cable. Trim 1/2 inch of insulation back from the end of the cable to expose the bare wires. Open the end of the clamp and position the cable at the end. Carefully close the opening by tightening the bolt provided. Make sure you tighten the bolts firmly so the cable can't slip out. Now, coat the whole clamp and a bit of the cable with a thin layer of petroleum jelly to protect it and re-attach the battery cables.

[scottamac]

on 6/11/2008 WRONG!!! Do not disconnect the positive first as anything your wrench touches while loosening the bolt will create a short circuit situation. ALWAYS disconnect the negative first as anything your wrench touches is also ground. Just be sure not to turn the wrench into the positive terminal when loosening the negative terminal as this is obviously a short circuit. Also, be careful any ring you may be wearing that might be contacting the wrench does not come into contact with the positive terminal while loosening the negative. Once the negative is disconnected, there is no danger of any "welding or shock" or whatever who wrote this thought as there is no longer a complete circuit (make sure you push the disconnected negative terminal away from the battery negative terminal after removing). Then when reassembling, connect the positive first and then the negative for the same reasons!
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