Auxiliary Light Power and Roof Mount Questions

[wantahertzdonut]

I have a Chevy Express and I'm adding a significant amount of auxiliary lights to.

The front bumper has 3 LED bars (brand/wattage unknown, they came with the bumper from the fabricator) and 4 Hella 500's (55W/ea). I also have 4 KC LED Daylighters (39W/ea) that I'm going to put up on the roof. My first question is how I can get power to these things. I know I could simply run power off the battery but I'd really like to have a switched circuit so the lights don't just turn on at any time, I only want them operable when the engine is running.

In my high school days, I used to just jam a wire into a fuse in the fuse panel but I'm sure there is a better method. I did buy a positive distribution block but I still need a switched power source to run it, so I'd like to know what people in the know do in order to get positive power (and quite a bit of it).

My other question is where I could get a roof mounted bar to mount the Daylighters. I'm not interested in a roof rack, just a gutter mounted bar would be nice, but I can't seem to find anybody that sells the clamps for the gutters, and I'd prefer a low profile clamp so the bar isn't sticking way high up over the roof. If I can get those, I'd just use some aluminum box channel to mount across the roof for the lights. Anyone have a lead on something like this?

 

[Hilldweller]

Can't help you with the roof mount (Thule?) but use this to wire your lights.
If the diagram doesn't make sense to you, find a reputable shop. Maybe pay them a bit extra to mentor you.

 

[rayra]

Relays to control the fat / direct power supply to the high-demand lighting. Allowing skinny low-amp wiring to dash switches, to control the relays.

 

[wantahertzdonut]

I have a bunch of pre-made Hella harnesses that are identical to the image above. What I'm after is where to connect the 12V+ VDC on the van. Do you guys just connect to another circuit in the fuse box, direct off the battery, or somewhere else?

 

[Hilldweller]

I have a bunch of pre-made Hella harnesses that are identical to the image above. What I'm after is where to connect the 12V+ VDC on the van. Do you guys just connect to another circuit in the fuse box, direct off the battery, or somewhere else?

I run a pair of 8 gauge wires off the battery to an auxiliary PDU and tap that for 12v. For lights that I want to turn on/off only when the Jeep is running, I use a parking light circuit as the trip. That way I won't forget and leave them on when the Jeep isn't running (idiot ding ding ding will sound).

 

[v_man]

I know I could simply run power off the battery but I'd really like to have a switched circuit so the lights don't just turn on at any time, I only want them operable when the engine is running.

What if you want to run your lights when the vehicle is off, like when you get into camp? Having the key in the ignition to run lights can be inconvenient. All my different circuits, lights, power stations, ham radio etc, can run wether the car is on or not, and that's a good thing.

I would consider adding an auxiliary fuse box like a BluSea. If you're adding these roof lights you're probably going to find other circuits/accessories to add. You don't want to end up with a rats nest of wires coming off the hot side of your battery or coming out of your stock fuse box...

 

[Hilldweller]

What if you want to run your lights when the vehicle is off, like when you get into camp? Having the key in the ignition to run lights can be inconvenient. All my different circuits, lights, power stations, ham radio etc, can run wether the car is on or not, and that's a good thing.

I would consider adding an auxiliary fuse box like a BluSea. If you're adding these roof lights you're probably going to find other circuits/accessories to add. You don't want to end up with a rats nest of wires coming off the hot side of your battery or coming out of your stock fuse box...

I use Blue Sea for my PDU also ------- my GPS, aux power outlets, ham & CB are all unkeyed but my lights are tripped by the running light circuit. Too many amps at stake with the aux lights and I don't want to risk leaving them on by mistake.

 

[wantahertzdonut]

I will have one light that I'll want to switch on without the engine running but it'll be off the back for loading and unloading motorcycles at night. All the rest I would prefer to have shut off when the engine shuts off. If I need them I'd be going into the van anyway to hit the switch, popping in the key won't be a bother.

I'll look into the circuits to see if I can steal power from there. I'm hoping the empty slots have power going to them since I assume they may be there for ambulance use or other upfitting. I'll try and get in there this weekend and see. If they have power then I'll be happy to use one of them.

What's this Blue Sea device you guys mention? I did a few searches and may have found something for boats, but the webpage has tons of options.

Eventually I'll run other lights for interior and exterior for camping but I'll wait till I get an auxiliary battery and an isolator for those. That'll be more for my Christmas break.

 

[v_man]

I was referring to a BlueSea auxiliary fuse box:

https://www.amazon.com/dp/B001P6FTHC/ref=twister_B01BXTXV1Q?_encoding=UTF8&th=1

I have them in both my 4x4's running off the second battery. Put a circuit breaker between the battery and fuse box and you have a quick disconnect for all circuits that run through the fuse box, plus it's way more tidy than running a bunch of power wires off your battery...

 

[Meili]

Whatever you decide to do, run dedicated grounds to the battery. The ground wire should be at least the same size as the power/positive side wire.

You can get a ground junction block so your battery does not looks like a spider.

Everyone ignores this half of the electrical circuit.I swear 99% of electrical issues are caused by bad grounds.

 

[wantahertzdonut]

A device like that is exactly what I had in mind. I ordered one just now, many thanks for providing the link.

I'll have dedicated ground too, I ordered a large gauge ground wire as well.