Adding electrical components such as lighting, audio gear, and alarms can present several safety issues even if the correct size wiring and terminals are correctly installed. To help with these issues, I ordered some products from Painless Wiring. 

Auxiliary Lighting Relay Kit 

Though I use the pre-wired factory fog lights on my TJ, I recently installed four "rock lights", or lights mounted under my Jeep to illuminate the trail on night runs. Because they are mounted so low on the vehicle, I bought 55w sealed beam lights that are sealed from water intrusion. We all know that water is an excellent conductor of electricity, and buying the wrong lights in this application could definitely give your electrical system a jolt!

 To wire up the lights, well, there is a right way and a wrong way. The wrong way is to run a wire from a hot wire to a switch, then from the switch to the light. In this case, either the switch or the wire won’t be able to handle the amperage the lights are drawing, or the lights will be very dim until the wire melts and shorts out, potentially damaging other parts of the electrical system.

The correct way to wire up auxiliary lighting (or any other high-draw accessory requiring a switch) is through a relay. Painless sells a very slick relay kit that makes this installation a snap. The kit contains a mountable switch, relay, and all associated wiring pre-wired and loomed for cleanliness and safety. I installed two of the kits to power four rock lights (each kit will power two lights) and installation took about thirty minutes.  

After mounting the switch (I used a different switch that fits better into my crowded dashboard), simply run its red wire to a fused power source, and its black wire to a solid ground. Then mount the relay with a single screw in a convenient area in the engine compartment. Route the red wire from the relay directly to the battery and ground the black wire.

Run the blue wire through the firewall and connect it to the empty terminal on the switch. Route the loomed wires to the area where you will install the lights, and then separate the loom into two sets of red and black wires. These will be hooked to the lights for power and ground. Mount your lights and that’s it! Simple, quick, safe.

The relay is basically a switch. It allows you to run a heavy "Power In" wire form the battery and equally heavy "Power Out" wire to your electrical accessory, while allowing you to run a smaller wire and switch. When you activate your switch and pass power through it to the relay, the relay switched on and allows power to pass through the heavier-wired circuit directly from the battery to the accessory.  

The relay kits come with a 30amp relay, and can handle a load of 360 watts maximum. This should be more than enough to cover most driving lights or fog lights, which usually don’t exceed 165 watts each (330w per set). The wiring included in the relay kit is also pre-terminated and of adequate size and length to provide the necessary power to your lights. 

Cirkit Boss Auxiliary Fuse Block

 

When wiring up lighting or other electrical accessories such as electric fans or CB’s, a fused power source should be used, whether it’s a hot or switched circuit. Fuses will protect your electrical system from a short circuit; plain and simple safety. Painless Wiring offers the Cirkit Boss, the first circuit isolator that provides both constant and ignition hot circuits. The extra fused circuits allow you to install auxiliary lighting and other modifications safely and easily. 

The Cirkit Boss uses thermal cross linked polyethylene wire rated to 250degrees @ 600 volts. All wires are factory machine terminated. Circuits are individually fused for up to 20 amp applications and use a heavy duty 30 amp relay. Every Cirkit Boss includes a 30 amp, in-line circuit breaker, relay, mounting hardware, and an assortment of terminal ends.  

The fuseblock is weatherproof and suitable for mounting under the hood. It also includes a rubber cover that snugly fits over the fuses to keep contaminants out. It mounts with four screws, and the relay is attached to the main fuseblock body. Simply run a power wire through a provided circuit breaker and directly to the battery, ground the fuseblock, and run another wire to a switched fuse on the stock fuse panel to sense ignition power, and you are ready to roll. 

The seven wires representing each circuit are each colored differently and labeled for easy identification. Simply choose a constant or switched wire, run it to the power wire of your new accessory, and splice them together. The auxiliary fuse block does not effect the performance of your stock electrical system at all, as it is setup to run as a separate set of fused circuits. 

Starter 

Its funny how some things happen…after installing all these electrical upgrades, I fried my stock starter on the Rubicon. This happened from over a year of trail use, using the starter to creep the Jeep along on the trail after a stall. When it stopped working, I was able to be push started and drove home, but rather than replace it with another stock starter, I spent a bit more money on a high-torque gear reduction starter. The difference between the two units is very obvious. The heavy duty starter does not strain when being used to start the vehicle in gear, and has a snappier startup mechanism. With this, I truly upgraded my entire electrical system! 

Conclusion 

Well, in the process of upgrading my entire electrical system, I learned much about automotive electrical, as well as many formulas and tips that apply to all wiring.  I, for one, hope that this system can handle all I can throw at it!  Based on my research and manufacturer's ratings, the trails ahead of me should be well lit and very safe!