Another fusing question
 

Got the aux. fuse box mod done today to get the taps out of the cockpits fuse box.

I went out and bought the exact same box and an inline fuse earlier today for my next project, cleaning up the other jungle growing out of control on my batteries positive post.

Question is, the new box I want to add will have an inline fuse with a rating of 30 amps.
I just remembered the the stuff I want to get off the battery are:
1. 30 amp relay for the rear lights.
2. 30 amp relay for the roof lights.
3. 30 amp relay for the bumper lights.
4. 30 amp relay for the loud horns.

The 4 taps that are now on the battery all feed those relays, which then send out the juice to juice the appropriate accessories.
Can this be done with the 30 amp fuse inline fuse, or do I have to step up to a higher one?
I am not sure how much amperage I need.

I don't run all the lights at the same time.
The rear lights are 50 watts at the most, and would not be used when the Hella's up front are being used.

The two sets of Hella 500's comprise of 4 x 55 watt lamps total.
The horns I don't know what they draw.
Thanks,

Nice install Corey.

Somebody correct me if I'm wrong, I'm no electrician, but I believe that in a DC circuit Power = Voltage X Amps. Since you know your power (or watts), divide that by 12 and you should get how many amps you normally use for that item. Probably a few more amps for initial power spike. So if you ran both 50w lights and all 4 55 watt lights you would end up with 320 watts, divide that by 12 and you get 27 amps, so a 30 amp fuze should be good as long as you don't switch on all your lights at the exact same instant while you are blowing your horn.

He he, I would have to be doin' a lot of multitasking there to turn them all on at once and blow the horns :D
Bill, if your answer is right on, it sounds like I should be OK.

Now I have to find a dang spot to mount the box. I was thinking of zip tying it to the plastic cover for the under hood fuse box that is behind the battery a foot.
Not much room under my hood is left.

You know, the 3 lamps relays are all on the firewall. I might be able to mount the box close by there and run shorter wire taps to the box, and just a longer wire from the box then to the battery.
Going to have to plan this one real good where to put it.

Thanks Bill, it's a nice feeling when you install something and it turns out half way decent ;)
Corey

Your math sounds good to me.

I've been thinking about this.

What guage wire will you be connecting to the battery? Depending on what else you might add later (like a power inverter) you might want to go with a wire and fuse that can handle a lot more current.

Also, I don't really know how much lights can spike, but they might spike a lot more than a couple amps :dunno: .

Steve

Good evening Steve. I will be using 10 gauge wire from the aux box to the battery.
That is the same guage I used today for the aux box I hooked up to clean up my in cab fuse box.

A power inverter might be down the road, but I'd probably go right to the battery for it, not sure.

I'd probably also be hooking up one of these in the near future, and I'd be hard wiring it instead of using their portabe setup. Not sure how much the pump would draw, I'd have to look into that too.
Corey