Common Grounds

[Lynn Miner]

This is less a modification than just good installation practice. More often than not, automotive electrical problems arise from poor ground connections. When one drills holes where ever it's convenient to mount a ground lug it creates one more location for a ground to get corroded and fail. When you have many such connections all over the place it only exacerbates the problem of troubleshooting a poor ground. It can also create ground loops that cause other problems entirely, especially when dealing with ignition systems. The intent of this write up is to describe how to make an effective single point ground.

Locate a convenient place to run all your ground wires. Drill a hole and install a Rivnut. These are available from stores that sell fasteners (like Grainger). You will need to buy the application tool also. These nuts are used throughout the assembly of the SPF GT40 so this is a small investment that can make life much more pleasant when doing the install on one of these cars. The nuts and tool are basically just a pop rivet gun with threads in the pop rivet.

Apply a liberal amount of dielectric grease to the nut before installation. This prevents corrosion and as a side note should be applied to virtually every electrical connection on the car. It keeps water out and will maintain a good connection for years. I even apply it to the base of all light bulbs where water can degrade the socket over time.

Now, route all your miscellaneous ground wires to this one point. It is a good idea to also run an engine ground to this same location.