Ground cables tend to corrode and cause various electrical malfunctions. A simple cleaning will clear up many problems.
Remove the ground cable at the firewall or fender and clean both the steel and the ring with a wire brush.
Coat the bare steel with dielectric grease and reassemble the connection. Then smear a dab of grease around the entire connection.
Do the needles on your gauges jump around, sweep from side to side or just plain refuse to budge? How about your other electrical accessories—do they work intermittently or so strangely that you swear they’re possessed? If so, it’s time to clean your ground cables.
The pros always start by cleaning the ground cables. Carmakers use the steel body as the return “ground” electrical path, so when the cables corrode (and they will corrode), the stray current can cause all sorts of strange behavior.
A rotary tool with a wire brush works great. But you can also use sandpaper. The key is to get shiny metal on all the connections. Use a shop manual to find the locations of the other ground connections in your vehicle.
Have the necessary tools for this DIY project lined up before you start—you’ll save time and frustration.
You'll need a rotary tool or sandpaper.
Avoid last-minute shopping trips by having all your materials ready ahead of time. Here's a list.