Grounding Kit - Installation Guide - Grounding Information
This guide is for the following Part Number.
PP-BTGK001-0
Main Installation Video
For Plastic Intake Manifolds - Bolt the ring terminal meant for the top of the intake manifold to the TGV block where the current ground terminal touches the intake manifold.
General Grounding Information
The most important thing to note about grounding is that you want direct metal-to-metal contact without paint, dirt, grease, or debris. A clean ground is a good ground.
Here is our Owner, Brian, talking with Flatirons Podcast and the IAG Podcast about the importance of grounding in your Subaru.
What is Grounding?
To ensure your car is running as efficiently as possible, we need to verify that our grounding system is functioning optimally. The most common analogy for how DC (car battery) current works is to think of it flowing like water from positive to negative. With that in mind, we can send all the power we want out from the positive side, but if our connection to the negative side is weak, there is no flow. With this in mind, having a good alternator and battery that produce a significant amount of power is useless without proper grounding.
When it comes to grounding issues, where do I start?
Grounding issues often serve as the root cause of many random and unusual electrical problems. Bad grounds can cause a range of unexpected symptoms, including the immobilizer not working, phantom misfires, and the ECU staying on all the time. It’s difficult to predict the pathways that ground issues will take. As mentioned earlier, electrical current flows in a similar way to water, so it’s going to find the path of least resistance, which might lead to it flowing where you do not want it. This can cause grounding issues to appear throughout the car, even if the faulty ground is located in the engine bay.
If there are unusual codes or check engine lights, we suggest checking the source of the issue described in the code first. If that looks good, then a way to eliminate another variable would be to add a grounding kit. Once you know that grounding is not an issue, you can then troubleshoot more.
When ground issues are commonly the problem:
TGV deletes or TGV spacers. The ECU gets its grounding from the top of the intake manifold. When you put a plastic spacer between the intake manifold and the block, as well as using the provided plated bolts that don’t conduct well, you lose the grounding to the intake manifold.
Painted manifolds, painted alternator brackets, or painted engine bays. The paint prevents metal-to-metal contact, so the ground is lost.
Big 3 Mod (The Big Three) and Grounding
The Big 3 Mod consists of an alternator power wire, grounding on the engine block, and grounding on the negative terminal on the chassis. Our grounding kit takes care of the last two, but we do not include an alternator power cable. It is rare that the power side of a circuit is causing the problem for engine functionality (except if the battery is dead). An alternator on a standard Subaru has plenty of power to run any of the standard features, so we’ve left it as is.
Installing the iWire Grounding Kit
Made with high-quality materials, the iWire Grounding Kit can be routed through the engine bay in any way you prefer. You can hide it away for a tucked look or just throw the grounding kit on top. You'll just mount the black junction block to your chassis and then use the ring terminals to bolt into the following locations:
The chassis where the negative battery ground touches
On the engine block
On the alternator housing
Intake Manifold
For Metal Manifolds - bolt to top
For Plastic Manifolds - bolt to the TGV block