Electrical Basics and Automotive Grounding Systems


The problem isn’t really the resistance of the wire, though.   Every single time you hook two wires together (such as with a connector), there is a small amount of resistance added to that Rw number up there.  That number is still very small in comparison to everything else; or at least it is when a car leaves the factory.

As a vehicle gets older, those connections get loose, dirty, and corroded.  All of that begins to increase Rw.  When that number starts getting bigger, your devices in the car start getting less power, because the overall resistance of the circuit is greater.  (Remember, higher resistance equals less current and less power.)  To make matters worse, the wires that connect the different parts of your car’s electrical ground system are often rather small to save money on production costs.  That means it is easy for them to become corroded or even broken. That higher resistance means your ignition system, computer sensors, fuel pump, and loud stereo aren’t getting as much power as they used to. 

Improving Your Vehicle’s Ground System
So what can you do to fix this problem?

HKS grounding system
HKS’s Circle Earth product is a supplemental ground system that lowers the resistance between the various ground points on your car.  It’s also very expensive.  But then again, HKS purple is a pretty color.  (Photo courtesy of HKSUSA.com)

You might have seen automotive ground kits like HKS’s “Circle Earth.”  It sounds too good to be true, though, doesn’t it?  Hook up a few wires to different parts of your car to get more horsepower and/or better throttle response?

Well, it is too good to be true.  Installing one of these ground kits onto a new vehicle will only make your vehicle faster by effectively performing weight reduction on your wallet.  However, installing that kit on an old vehicle with worn out grounds can actually restore lost power by lowering the resistance to ground.  You may also consider installing a grounding kit on a vehicle that has an aftermarket standalone ECU, especially if you’ve done a lot of hacking up of the wiring harness.  

1 comment

  1. Very good read. I would just add a word of caution when tieing Electrical Ground to Signal Ground especially in newer vehicles with more onboard electronics. The Electrical Ground provides the voltage differential to insure things like Spark Plugs work well. However, spark plugs (and wires) also generate lots of signal noise that electronics do not fair well with.

Leave a Reply

Your email address will not be published. Required fields are marked *