How to Build and Install a DIY Grounding Kit for G37, G35, and 370Z
Upgrading your factory ground wiring is a proven garage project that cleans up automatic transmission lag and sharpens throttle response. You can build this exact kit at home with basic electrical supplies and an hour of your time.
The Short Answer (TL;DR)
Building a DIY grounding kit for your G35, G37, or 370Z takes about an hour and $35 in materials. By installing 8-gauge oxygen-free copper wire between the chassis, engine block, and negative battery terminal, you reduce electrical resistance. This firms up shifts on 5AT and 7AT transmissions and cleans up audio static.
The DIY Process Overview
To build the kit, you need 12 feet of 8-gauge oxygen-free copper wire, six 8-gauge ring terminals, three 4-gauge ring terminals, a wire stripper, and a heavy-duty crimping tool. The installation requires a 10mm socket, a 12mm socket, and a ratchet to secure the new grounds. The completed harness consists of three separate cables: the passenger side wire, the driver side wire, and a center connecting cable.
Disconnect the negative battery terminal and remove the engine shroud to begin. You will make nine total connection points across the engine bay. The primary grounding locations include the negative battery terminal, both driver and passenger side wheel well bolts, the engine block near the intake, the dipstick mount, and the driver's side strut tower.
Measure twice and cut carefully, leaving a little slack so the cables do not rest directly on hot exhaust or engine block components. Crimp the ring terminals securely and use heat shrink tubing over the connections to prevent corrosion. Once everything is bolted down tightly, reconnect the battery and reinstall the engine cover.
Why You Should Upgrade While You're In There
Since you are already working around the intake tubing and throttle bodies, this is the ideal time to install aftermarket bolt-ons. Upgrading your restrictive factory airboxes to a cold air intake system maximizes the improved throttle response you get from the grounding kit. Having the engine bay taken apart makes routing intake tubes significantly easier.
To get the most out of faster transmission shifts and increased airflow, a custom engine tune is the next logical step. A proper tune will optimize your air-fuel ratio and transmission line pressures for maximum reliability and power.
Recommended Upgrade: Cold Air Intake System and Engine Tune
Frequently Asked Questions
Is building a custom grounding kit difficult?
Not at all. Stripping and crimping the heavy 8-gauge wire is the most labor-intensive part. The actual installation simply involves removing 10mm and 12mm bolts in the engine bay, sliding the new ring terminals over them, and tightening them back down to factory torque specs.
Does a grounding kit actually make my automatic transmission shift faster?
Yes. The factory ground system degrades over time, creating resistance. By routing low-resistance, oxygen-free copper wire directly to critical sensors and transmission grounding points, the ECU and TCM receive cleaner voltage signals. This reduces the hesitation and shift lag commonly found in the Nissan 5AT and 7AT transmissions.
Why did my automatic windows stop working after the install?
Whenever you disconnect the battery on a Nissan or Infiniti, the window auto-up memory resets. To fix this, turn the ignition to the ON position, roll the window down more than halfway, then pull the switch up to close it. Hold the switch up for three seconds after the window closes completely to reset the calibration.
