Proper electrical system grounding is one of the most misunderstood aspects of the automotive electrical system. However, a properly grounded electrical system is vital to the performance of your vehicle. Without a good ground, your ignition system will underperform, you’ll experience random issues with charging, and you can easily end up stranded.
A basic ground system is as follows:
- Always use a heavy ground cable and connect one end to the negative battery terminal, and the other end to the starter motor or engine block as close to the starter as possible. This will insure the correct ground path to the starter motor.
- Ground the engine block to the frame with a heavy ground wire or cable, making sure that both connections are clean, tight, and metal to metal.
- Next, ground the engine block to the vehicle body with a heavy ground wire or cable making sure that both connections are clean, tight and metal to metal.
- If you have a fiberglass body you will need to attach several heavy ground wires to the engine block. Run one to the rear, two to the dash area (if you have a lot of accessories), and one to the front.
Each individual ground can be routed to a central location and all of the components in that general area can be grounded to it.
NOTE: Make sure that the wire or cable for each ground has enough length so that when the engine torques (moves under a load) the ground will not be pulled apart.
In terms of actual wiring, you want to use at least 14 gauge wire for the body ground (see our ground kit for more info). A braided copper ground strap is best attaching the engine to the frame. Heavy #2 gauge cable should be used to connect the battery negative terminal to the engine block or starter mounting bolt.
Finally, insulated wire is best if you’re running wire for any sort of length. Insulation ensures that the wire will not deteriorate due to moisture.