I get asked a lot about how I did my battery relocation. While there are many many different ways you can do it with various amounts of different parts and products, I believe my way is one of the simplest. But, I chose to go the way I did because it worked with my wire tuck and setup nicely.
I would also like to say that my method isn’t necessarily the safest. There are many things you can apply to a battery relocation, such as in-line fuses and circuit breakers, to make the relocation safer. I did not add any of which to my personal relocation.
My battery relocation diagram also uses a kill switch that I mounted on the rear bumper of the car. A kill switch mounted on the rear of the car is commonly used in battery relocations as it is in the NHRA rulebook that any car in competition must have a kill switch on the rear of the car, labelled ON/OFF. This allows track safety officials to easily and quickly kill power to the car after an accident to prevent electrical fires, etc.
I made this diagram prior to actually doing my battery relocation so I had a clear gameplan heading into the relocation. There are, however, two things I ended up doing differently than what is shown in the diagram.
I run (2) ground wires off of my battery directly to the chassis (right rear strut tower studs. Any time you add a new ground to the chassis, be sure to remove any paint below the contact point. You can use sand paper, grinder, etc.
I run (1) ground from the bell housing of the transmission (starter bolt) to the firewall. Again, grind the paint off of the area you are attaching your ground to.
Something that I recently started doing this year was adding a ground from the alternator casing to the chassis. I added my ground to the alternator tensioner bolt.
All grounds are either 0AWG or 2AWG wire.
My kill switch is now mounted to the center tail light section instead of in the right reverse light on the back bumper. I had a problem with water getting up in there and affecting the connections so I moved it up into the center tail light piece.
I run a main power wire (0-2AWG) from the positive terminal of the battery to the lower post on the kill switch. From the same post of the kill switch, I run a 0-2AWG (or maybe a 4AWG) wire from that post all the way up to my alternator post.
Make sure you use a large ANL fuse holder with a 100A or larger fuse in the new alternator wire. Most DSM alternators are 75A-90A. If you upgrade to a larger amp alternator, you need to increase the amp size of your fuse. You can also remove the old alternator wiring that used to go to the alternator.
On the other post of the kill switch, I run a 4AWG wire to a distribution block. I also run my 10AWG wire from this post to my fuel pump rewire relay. When the kill switch is turned off, it kills power to my fuel pump and distribution block.
The distribution block “distributes” power to multiple places. One 4AWG wire runs directly to my starter.
I do not use a factory fuse box anymore, but you would also run a 4AWG wire from the distribution block to the side post on the fuse box in place of the old power wire.
1G’s have 3 or 4 fusible links connected to the positive terminal on the battery.
- Ignition Switch Circuit Fusible Link – 30A
- Radiator Fan Motor Circuit Fusible Link – 30A
- MFI Circuit Fusible Link – 20A
- ABS Circuit Fusible Link (if equipped) – 60A
You need to use ANL fuse holders with a proper size ANL fuse for each of these. Or, you can use 1 single ANL fuse holder with a larger fuse equivalent to the total amps needed. I recommend doing the first choice with multiple ANL fuse holders.
From the other side of the ANL fuse holders, you would run a 10AWG wire to whatever it’s supposed to go to. All you have to do is cut the old factory fusible links off of the harness and run new power wires. You could just leave the old wires that run to the factory wiring harness.
Now, here is a list of parts/products/material I used:
In-Line 100AMP ANL Fuse
ANL Fuse for the MPI/IGN Fusible Links
I used 4AWD on the following:
Alternator to Fuse Box
3 Fusible Links (MPI, IGN, RAD) to Distribution Block
Fuse Box to Kill Switch
Distribution Block to Starter
I used 2AWG on the following:
Positive terminal of the battery to the kill switch
Kill switch to the distribution block
Bell housing to firewall ground
Negative terminal to the rear strut tower chassis ground