How to Add an Auxiliary Fuse Box

[Vinsanity92]

Are you struggling to find a circuit that you haven’t tapped yet? Or are you just worried about grabbing the wrong circuit or you just don’t want to mess with your factory wiring? Well then have I got the add on for you it is called the Blue Seas Fuse Block It includes 6 positive fuses and 6 negative lugs with a large positive lug and a large negative lug.

So I am slowly adding aftermarket items to the expy and being a boater I had used the Blue Seas Fuse block with negative posts before. I find that it makes installations much easier as I don’t have to run wires off of other circuits and I don’t have to run wires to bare metal to ground the same items.

Tools List
- Wire strippers
- Wire crimpers
- trim removal tools
- 7 mm socket (internal screw removal)
- 11mm socket (removing the battery terminals)
- Wire snake or wire coat hanger will substitute
- wire lube or 3 in 1 oil
- Multi - meter (or a 12v item to test you have power coming from the fuse block)

Parts List
- Blue Seas Systems 5025 ST Fuse Block - $ 34.99 Amazon Prime
- http://www.amazon.com/Blue-Sea-Syst...qid=1389670091&sr=8-1&keywords=blue+seas+fuse
- WirthCo 30103 Tapa Circuit for ATM Mini Fuse Blocks - $ 8.80 Amazon Prime
- http://www.amazon.com/WirthCo-30103...&qid=1389665090&sr=8-1&keywords=tap+a+circuit
- Novita/4 pin 40 Amps 12 Volts accessory relay - $ 6.99 Autozone
- Black Primary wire 18 ga. 25ft - $ 6.99 Autozone
- Red Primary wire 18 ga. 25 ft - $6.99 Autozone
- Black Primary wire 10 ga. 100ft - $35.00 wireandsupply.com
- Red Primary wire 10 ga. 100ft - $35.00 wireandsupply.com
- 10 ga ring terminals - 4
- 18 ga ring terminals - 1
- 10 ga female disconnect - 2
- 18 ga female disconnect - 2
- #8 x 1 Sheet metal screws - 2

Usually I have primary wire laying around for other projects and such that’s why the price is for a 100ft spool from wire and supply. They have great pricing on wire put simply for 25ft of 10 ga. from autozone it comes out to $ 20.99 for $ 15 more I could have 75 more feet. I just so happened to run out of the 18 ga I had and I caught a nice day on a weekend I couldn’t pass up so I ran to autozone and bit the bullet and paid a little extra for the wire.

Some post pics of the install can be seen here

https://www.dropbox.com/sh/6s5wq037duvxkkd/wIkHAloZkx

First things first I had to decide on a place to mount the block. I found a nice flat easily accessible spot on the plastic kick plate on the passenger side of the truck next to the emergency fuel cutoff.

Now before you start any wiring at all disconnect the positive and negative cables from the battery and remove the battery for now. It will let you work in the engine bay a little easier. Also this is just safe practice should you accidentally touch the two wires it will keep you from shorting them out.

I Used 10 Ga. wire to go from the battery through the firewall to the blue seas fuse block.

On the positive side I used a heat shrink ring terminal on the factory battery lug to a 40a inline-fuse which then runs through the firewall across to the passenger side glove box to a 40a relay to switch power on and off when the key is turned in the ignition. Then it runs to the positive supply lug on the Blue Seas Fuse block.

The negative side is grounded to the bolt right in front of the battery in the engine bay using yet again a heat shrink ring terminal. Then it runs through the firewall. I then tucked the wiring behind the carpeting against the firewall snaking around the center console to the passenger side straight over to the negative lug on the Blue Seas Fuse block.

In the process of running all of the wiring I removed the driver side kick panel the center console as well as the glove box on the passenger side. This way I was free to run the wiring as I wanted to without having to snake it through all of the trim. When running the pos and neg through the firewall there is a single rubber grommet that is below the brake booster and exits to the left of the brake pedal inside the truck. I ran into an issue getting the wiring through this grommet easily. I had to use my wire snake lots of electrical tape to hold the wire to the snake and some wire lubricant to get it through the grommet. Once through the grommet it was easy to feed wire through.

The relay is controlled by a separate ignition switched power source. I ran 18 ga. wire from the driver side fuse box to the control side of the relay. It runs alongside the 10 ga. wire. Then using the negative terminal block on the blue seas fuse block I grounded the relay. The fuse I tapped onto was #19 which is the Restraint Control Module it is a 20A fuse but that doesn’t matter because with the tapa circuit you still protect the original circuit at the same amperage you just add the fuse for the relay circuit.

Now turn the key and break out your multimeter and test that you are getting clean consistent power from your Aux Fuse box if you wired everything correctly you should be reading 14.whatever your alternator is running at.
Phew Now that you’re finished pop a cold one and plan the other things that you are going to run off of this wonderful new addition to your truck.

I wouldn’t run an inverter off of it unless it’s a 200w the 400w peaks at 31 amps when drawing full and combined with the 5 other circuits on there it may be too much. But you can use this to power a radar detector, Sirius external receiver, cb radio, backup camera, led lighting, and damn near anything that needs power inside your truck.

If you upsized the wire to 8 or even 6 ga. you could run higher amperage devices off of the block but you will need to drill through the firewall and I really didn’t feel like doing that nor did I have anything that would draw that much power.

Ill be adding some pics soon.

 

[BlkSquad]

Nice write up, waiting on pics.