Sale ends todayGet 30% off any course (excluding packages)

Ends in --- --- ---

Grounding fibreglass car with trunk mounted battery

EFI Wiring Fundamentals

Forum Posts



Tech Articles

Discussion and questions related to the course Motorsport Wiring Fundamentals

= Resolved threads


Hi , Would it be advisable to run a 8 gauge ground and power circuit directly from battery to terminal blocks under dash where I could supply power and ground to all vehicle electrical systems including ECU.MSD.wideband ,and vehicle fuse panel. The only exception would be Battery cables (2g) which would run to chassis for ground and positive cable for starter power. Engine block would be grounded to chassis and would also run a 8g ground from engine to ground block under dash. Thank you

Attached Files

I guess your chassis is still made up of conductive material, so I would only use the chassis as the main ground, and the engine block for everything ECU related. Like this you would still respect the star earthing point rules.

In the diagram, you have two grounds for the ECU, etc.

This will act as a secondary ground for the engine back to the battery and introduce ground voltage fluctuations as devices grounded to the engine and/or chassis are turned on and off, especially the starter.

Using a single, suitable gauge, ground wire to the battery for the ECU should be the best option.

First thing I do to any chassis wire/rewire is mount a distro lug in/near the engine bay and in/near the rear of the vehicle. They're either directly terminated to the battery or to the (as short as possible) ground strap from battery to chassis.

We usually reply within 12hrs (often sooner)

Need Help?

Need help choosing a course?

Experiencing website difficulties?

Or need to contact us for any other reason?