Things You'll Need:
- Wire brush
- Battery
- Battery cables
- Wrench
-
Step 1
Lean over the battery inside the hood of the car and look for the battery terminals. Compact cars may have the car battery turned on its side.
-
Step 2
Read the signs at the base of each terminal. One will have a plus sign, the other a minus. Plus is positive and minus is negative.
-
Step 3
Take a wrench and loosen the bolts on the battery cable. Loosen the negative one first. Clean one terminal and cable at a time, and then do the other.
-
Step 4
Wiggle the cable end to help remove it from the terminal post.
-
Step 5
Use the stiffness of a wire brush to clean the battery terminals and cables. It's important to have both clean for a strong connection. Insert the wire brush into the cable end and twist.
-
Step 6
Check for frayed ends on the cable and replace if necessary. Don't try to repair cables, as replacing them isn't expensive.
-
Step 7
Blow and wipe away dirt and corrosion from the battery terminals and cables, then reconnect.
Comments
bobpaul said
on 12/17/2008 Ok, now a comment. A year ago my car wouldn't start and the reason was bad clamps/corroded battery cables. I cut off about 6-8" of battery cable that was bad and installed new clamps. Now my car was having the same trouble (key turned to on, every thing OK: gauges move, lights turn on, fuel pump pressurizes; turn key to start and all electronics die for about 3-10 minutes as if I tripped a self resetting fuse).
Again it was corroded battery cables, but this time the corrosion hadn't gone too far, just enough to block conduction between the cable and the cable clamp. I removed the clamp, washed the cable ends with baking soda/water and scrubbed with steel wool, and put the wires back in the clamp. I didn't get all of the corrosion off and will need to replace the cables later (hopefully when it's warm, so I can do it myself) but that's all I needed to get the car starting again.
bobpaul said
on 12/17/2008 First off, in step 3, it should read "Remove the negative terminal first." Whenever working on the electronics of your car, always remove the negative terminal and leave it disconnected until you are done. This is because most cars are negative grounded (that is, the negative wire connects to the frame) and if you accidentally short a tool from the frame to a positive wire or the positive terminal, you can throw a spark with more current than most arc welders! For the same reason, remove wrings and metal watches, as if they are part of the path (box end wrench from positive battery cable to wedding ring to car frame) they can get very hot and cause severe burns. If your car is positive grounded, remove the positive cable first and leave it disconnected until finished. Car batteries are designed to pump a lot of current (up to and over 1200A) when requested, so be careful. Remove negative
robbinmco said
on 11/29/2008 It was easier and inexpensive (under $12) for me, to replace a section of the battery cable. I have a 1989 Nissan Pathfinder, with aftermarket attachments coming off the positive terminal. The "universal" positive battery cable was impractical to replace. An "important" black wire was corroded throughout, causing a voltage draw to kill the battery and disabled various electronic things in the truck (interior lights, headlamps, radio). Replacing this cable (with a piece of a small 10 guage roll bought at the parts store, plus a crimp-end aftermarket wire to attach to the termial was the way to go. After exhausting searches online (hey, lost in the links)that led me nowhere, I feel the need to share this.