I'm toying with the idea of putting in some auxillary lighting on my Land Rover Discovery. It's not a particularly popular car with a pretty sparse aftermarket, so I'm kinda having to come up to speed with figuring this stuff out myself (as opposed to just looking at what others have done).

The battery and fuse box are in the back of the vehicle, behind and above the rear
passenger wheel. There is a "main" positive (+) lug/terminal under the hood (as well as a chassis ground (-)), right above the front passenger wheel.

Having the battery in the back, but with access to a positive terminal (capable of jumping or charging the car) in the front poses both opportunities and challenges. Fog, auxillary driving spots, and floody ditch lights can be wired up in the front, relayed up to the 12v lug/post under the hood, and a single wire controller can be run through the firewall to the driver pretty easily.

Here, comes my first question: If I wanted to install a rear "scene" light, I would have plenty of space for a relay and can directly wire it up to the 12v starter battery back there. How though, should I run the switch wires from the back of the vehicle to the front of the vehicle to the controller? What are my options? What's the recommendation?

I see:

(a) using a stick-on rubber gasket/channel across the roof and down the A pillar into the engine bay;

(b) zip tied and wire loomed up underneath the vehicle (plenty of splash shield/skid plates from the factory to hide behind);

(c) along the floor, under the carpet and under the floor sills/trim (I recall having done this with the 12v wire for my stereo amp and subwoofer back in the early 2000's for a Dodge Durango);

(d) Maybe something up in the headliner?

Anyway, looking forward to hearing people's thoughts, especially from people who have car audio or offroad lights themselves.

I'm also planning a auxillary reverse lights, but that would just be switched/piggybacked on with the OEM reverse lights into a relay and powered directly off the 12v battery.

(e) Any or all of the above.
Whatever is the easiest, then shortest, path. If it's outside, protect the wire from the elements, if it's inside, protect it from anything sharp or abrasive.

I deal with OEM wiring & the few times we've had to retrofit, the above sentence is what we follow. Under carpet or in headliner is usually least-effort inside. Make as few holes to the outside as you can. Never looked at a LR, but I'd be surprised if there's not a fuse/relay box under the hood & a smaller one in the dash. We're up to 4 (2 under hood, dash & rear) on multiple vehicles now.

With any additional added wireing be it off the front positive post lug or the rear battery location pleas add a approperate size fuse as close to the power source as possible.. This would keep the extra hot (electric power source) wire as short as possible and not having a long length of hot wire under the hood with nom true destination. .............................. drill sgt.

quote:

Originally posted by drill sgt:
With any additional added wireing be it off the front positive post lug or the rear battery location pleas add a approperate size fuse as close to the power source as possible.. This would keep the extra hot (electric power source) wire as short as possible and not having a long length of hot wire under the hood with nom true destination. .............................. drill sgt.

Many, many fuses, everywhere. lol. The idea of a car fire or messing up electronics is really unappealing to me.

I would find a good location for an accessory bus which is powered via solenoid when the accessory circuit is hot. Then run non-essential add-ons all off that bus, fused for each circuit of course.

They make fancy switches for this purpose now, this is a popular one: LINK

quote:

Originally posted by AKSuperDually:
I would find a good location for an accessory bus which is powered via solenoid when the accessory circuit is hot. Then run non-essential add-ons all off that bus, fused for each circuit of course.

They make fancy switches for this purpose now, this is a popular one: LINK

Yup, looking at exactly that (or similar by Nilight).

I ran wiring for rear lights and a 5000W inverter on my FJ.
I ran it through Velvac split loom tubing and ran it along and under the inside of my truck.
I taped it every 4 inches and used zip ties where possible.
I was a good bit of work, but with a 2ga. cable and 6 wires to keep from shorting out, it was worth it!
I used a Waterproof relay/fuseblock I got from Grainger for my control system.
I've push water over the hood in my FJ!

You don't have to have fuses everywhere, just one as close to the power source as possible. And at an amperage just above what you're powering calls for.

I've run more wire in vehicles than I care to think about. My go to is usually along the floor of the vehicle, underneath the trim there are usually channels big enough to slip in extra wiring. You can go along the top trim as well/in the headliner. But it's usually a little trickier and if the vehicle is newer, you have to watch out for side curtain airbags to avoid interfering with them.

They ran all the wiring in our patrol cars under the rug next to the doors or thru the door molding. Some of the cars had cameras CPU in the trunk and power from the hood, then wires back up front to the camera via the A pillar and back to the CPU.

All the stuff in the center console, computer, switches for the lights, siren, radio was in black tubing and run over the carpet to the firewall and thru to the battery and all the items were along that center hump so the wiring to the item terminated there. Except the lights on the roof, and they ran the wire bundle under the rug behind the driver seat and up under the B pillar molding to the roof where they drilled a hole.

All the wires were fused under the rugs in the cabin, not near the battery. I have no clue how we didn’t burn up any cars due to the wiring.