Flex Innovations Big3 Grounding Kit Walkthrough

The F.I. Big3 = Engine (near Alternator Negative) to Chassis, Negative Battery terminal to Chassis, Alternator Positive to Battery Positive.  (Power Wire is Fused with 150AMP Wafer fuse in case)

DISCLAIMER: THE INSTALLATION OF THIS KIT TAKES A SLIGHTLY HIGHER SKILL LEVEL THAN THE GROUNDING KIT.  THE MAZDASPEED3 ENGINE BAY IS MORE COMPACT AND TO ACCESS SOME CONNECTION POINTS YOU MAY HAVE TO REMOVE THE TOP MOUNT INTERCOOLER.  (THIS IS A FEW BOLTS AND SOME HOSE CLAMPS)  IN ADDITION, THE MOST DIFFICULT PART MAY BE ACCESSING THE ALTERNATOR POSITIVE TERMINAL.  IF YOU ARE SKEPTIC OF YOUR ABILITIES, TRY TO ACCESS THE POSITIVE ALTERNATOR TERMINAL OF YOUR ENGINE BEFORE ORDERING THE BIG3 KIT.  IF YOU CAN ACCESS THIS, THEN INSTALLATION WILL BE A BREEZE.

IF YOU FEEL COMFORTABLE WORKING WITH YOUR CAR AND WANT AN EXTREMELY EFFICIENT ELECTRICAL SYSTEM THEN THIS KIT IS FOR YOU.  LEAVE YOURSELF ABOUT 2 HOURS FOR INSTALLATION.  (INSTALLATION IS NOT HARDER THAN INSTALLING SPRINGS, BRAKE PADS, OR CAMBER KITS SO IF YOU CAN DO ANY OF THOSE THEN YOU CAN PROBABLY INSTALL THIS KIT)

Basic Tools:  Metric Socket set. (Especially 10mm & 12mm).  Metric wrench set may help, in addition to socket extenders.

Instructions:  First organize the Wires from Shortest to longest.  The shortest wire is “Wire1”, the second shortest wire is “Wire2”, and so on till you have the longest wire which is “Wire4”.

INDEX MAP (USE THIS IMAGE FOR INSTALLATION)

THIS MAPPING IS ONLY INTENDED TO BE A "GUIDE".  The routing and connection points you choose may be different so feel free to be creative or adapt the kit to your specific engine.

Wire1 = Battery Positive (Bolt P) to Wafer Fuse

Wire2 = Battery Negative (Bolt B) to OEM Chassis (Bolt C)

Wire3 = Engine Bracket above Alternator (Bolt D) to OEM Chassis (Bolt C)

Wire4 = Wafer Fuse to Alternator Positive (Bolt A)

Note: First connect wire 1 to the fuse and then wire 4 to the other end of the fuse.  The other end of wire 1 will connect to the positive battery terminal.  The other end of Wire 4 will connect to the positive alternator terminal.  (This is called Wire 1 + Wire 4).  Don't connect the fuse just yet and please disconnect the negative battery terminal so that you don't cause an electric short and BLOW the fuse during installation.  Cover the terminals with a shop towel so you don't drop anything on the terminals.  Just use common sense and you will avoid un-wanted sparks.

Note: The smallest ring connects to the negative battery.  The largest ring connects to point "D" which is the engine.

Note: Wires 3 and 4 go OVER the engine block.  This image shows a FMIC speed3.  If you have the STOCK speed3 then your wires will go UNDERNEATH the factory top mount intercooler.  Keep the wires away from the turbo and turbo manifold.  Secure wires with zip ties away from hot components if applicable.  These wires are HIGHLY abrasive resistant so it is ok to have them touching plastic and metal edges.  At connection points, you may bend the ring terminals carefully to prevent the 4ga wire from having to bend at too sharp of curves.

WIRE 4 - Alternator Connection (Bolt A):

To access the alternator you may have to first remove the foil heat shield that is between the manifold and fire-wall.  This removes with just two small bolts.  After you remove this foil heat shield, you will have more room to remove a black plastic cover which protects the alternator.  To remove this black plastic cover you need to find two bolts securing the plastic cover.  One bolt is easy to find and around the top middle of the black plastic alternator cover, the other bolt is about 4" beneath the first bolt and is well hidden from view.  You will have to feel with your hands where this bolt is, and then use a socket wrench with a 2-3" extension.  Of course if you have a Mazdaspeed3 service manual you can look up how to service the alternator.  Or you may search your favorite Mazdaspeed3 internet forums.

There is a plastic cover on the alternator positive terminal that is gray and looks like this. 

 WIRE 1 – Battery Positive (Bolt P):

WIRE 2 - Bolt B (Neg. Bat.) to Bolt C (OEM Chassis)

Route wire 2 down through the battery box and to location "C".  By doing it this way you will not have to cute a hole in the side of the battery box. Remember that point "C" will have 3 ring terminals total connected at that chassis point with one of them being the existing OEM grounding wire.

Note: Some people "CLEAN" their oem grounding point with a wire brush and scratch off some of the paint where the OEM grounding point makes contact with the chassis. I have found that the connection to the chassis is mostly due to the threaded area, however please feel free to improve upon the factory grounding point.

Wire 3 = Bolt D (Engine) to Bolt C (OEM CHASSIS)

This wire routes along side wire 4.  It connects anywhere you want on the top of the engine block.  I had to remove the intercooler to access a bolt near a bracket that is above the alternator.  MAKE SURE YOU DO NOT CONNECT THIS WIRE TO YOUR ALTERNATOR POSITIVE!!!.  Instead you want this wire to connect to a ground which is the bolt holding the pictured bracket to the engine block.  This wire runs UNDER the intercooler to go across the engine.  Do not run wires over the exhaust manifold since this surface can reach high temperatures that may cause damage to the wires.  Allowing the wires to touch the engine block is OK since the engine tends to not exceed 250 degrees F.  Keep in mind that it takes 500 degrees to begin melting the sleeve of the wire.