There are several methods to wire or run a cable from the roof along the rear to the engine bay.

We have listed the method, in order based on the preferences of how professionals would do. It could be auto electricians, or 4×4 shops, almost every expert installs this way.

If you think running wires from the roof is easy work, you’ve got it wrong. It’s not a plug-and-play method, so it’s pretty complex. You need to have a certain amount of auto-electrical understanding.

It’s important to select an ideal wiring gauge. You should also know how to terminate and join the wires because of the length of wiring needed apart from the already offered wiring harness.  

Along the Side of the Windshield.

This method is based on the type of the vehicle. Some vehicles don’t have windscreens that will allow this method, no matter what.

Usually, the wire is taken from the light to any 12v supplier’s heavy gauge wiring that has a twin core. This will be placed on the windscreen’s side. Once that’s done, it’ll be mounted using ideal silicon adhesive.

Along the Rear of the Cab.

When the wiring is less discreet and is in lineal meters, it’ll be much longer. Anyway, it’s one of the methods used by experts. This method only requires cable ties to mount.

The cable is taken along the roof’s length. The roof is fixed to the roof rail or rack. When considering a UTE, it’s usually looped across the tray’s headboard or sports bar.

It then proceeds towards the chassis rail and then moves towards the engine bay.

Down the Snorkel Head

This isn’t a common method. However, you can loop the roof light bar’s wire into the snorkel head’s back.

After installing it in the snorkel head, the cable will extend down into the airbox’s dirty section. This requires drilling of the airbox’s side to pass the wiring and reconnect it to the engine bay.

(Note: you need to completely seal the opening of the airbox, and you should test it before trying potential river crossing) .

Drill It Through the Roof

This is a method most don’t prefer. The reason is it can’t be reversed. As the name suggests, this method is pretty self-explanatory – you have to drill a hole through the roof’s skin.

Once that’s done, the wire will run into the rubber grommet into the hole in the roof. It’ll then go down into the car’s body.

Please know that these options are just for guidance only. When you are fixing these, it’s best to talk to a professional auto electrician about the minute details of the installation process.

You can also ask from 4×4 shop if you have any doubts. It’s also important to find the right wire gauge before installing.

Traditionally, we have regularly enclosed our wiring within flexible, convoluted tubing known as conduit.

Due to this, the wiring is completely durable, but there are some challenges when running it up the windscreen glass’s side. The next best option is to run the sheathed harness in between the A-Pillar and windscreen glass.

Anyway, here are some reasons why this is a less ideal solution:

1. You will not find a gap between the A-Pillar and windscreen glass in every vehicle model, so it’s not possible to run your harness.

2. Even if you have a vehicle that has an ideal gap, you shouldn’t run a sheathed cable as it’s not safe. Mainly, if you’re using it for off-roading.

3. If you have already run or planning to run various solutions, including work/camp lights, reverse lights, a light bar, and other types of accessories, then this might not work. This is because there will be several harnesses so the gap won’t be enough.