The negative terminal can be located by looking for the letters “NEG” or the negative symbol (-) on the battery. You will not need to disconnect the positive cable.
You will need to identify the location you intend to mount the spot light first in order to cut the proper lengths of wire. Remember that if you install the spotlight on your roof, you will have to drill through it, which may cause leaking.
Halogen lights will be the cheapest and usually the dimmest. However, the bulbs are less expensive to replace when they blow out. LED lights can be extremely bright and cost more than most halogen spotlight applications. HID lamps are the most expensive, but offer the longest lifespan and often the brightest lights.
Even if the light has a switch, you may still choose to run a switch into your vehicle. Determining where you want the switch will help you establish how much wire the project will require.
Try to avoid mounting the relay too close to the exhaust manifold, as the heat may damage the relay. You can use heavy duty double sided tape, an adhesive, or drill holes through the metal to mount the relay.
This wire will provide the ground for the relay circuit. Whenever possible, use black wiring for grounds to make them easy to identify.
This fuse will protect the spotlight and the relay from surges if there is an issue with your electrical system. The fuse will blow out if too much power flows through it, cutting the power and preventing a fire.
This wire will provide the power to the relay, and then the spotlight itself. Ensure the cable to securely fastened to the positive terminal. If it jostles loose, the spotlight will fail to function.
Soldering the wire is the strongest and most permanent way to connect the wiring to the spotlight.
If you are unable to run the wire through the firewall, tuck it through the corner where the hood, fender and driver’s side door meet. Be careful not to run the wire through anything that may melt or break it in the regular use of your vehicle.
If you choose to mount the light on your mirror, you will not need to use any weather proofing. Mounting a spotlight on a light bar or otherwise attached bracket will also require no drilling or weather proofing.
If you choose to use a button instead of a switch, it will mount in the same way. Ensure the switch is someplace easy to access without looking to be able to use the light while you drive.
The switch needs its own ground and power source to function properly.
Be sure to put a fuse in the fuse holder to power the switch. Check the instructions for the spotlight and ensure you use a fuse rated for the amperage needed for the light to function.
Reconnect the battery and test your new spotlight. If the light fails to turn on, ensure none of the wires have been pulled off their terminals or been crimped to interrupt the flow of electricity.
