Currently I have my aux. accessories in my H3 tapped into one of the cigerette lighter's power, but I don't want to overload that line (which I doubt would happen), so I want to tap into something else for my new toys I'll be installing. Is there any 12V source under the dash around the steering column that I can use where I don't have to take the center console faceplate off to access? I don't have a wiring schematic of the H3's interior so I can't trace any lines, and I don't want to cut into anything that is critical for the car. If anybody knows the color or specific 12V line hot wire I can use, let me know where it is and the color code. Thanks!

I'm going to be installing a 5.6" monitor and a separate DVD player/TV Tuner combo unit. I doubt they draw much power, but if you guys think i should just keep using the cigarette lighter power, I will. Right now I have my laptop GPS reciever (which only draws a few watts), laptop power adapter (which is rarely drawing current since I hardly use the laptop in there) and the FM modulator for all my sound stuff. The radar detector works off the power to the mirror.

 

The media stuff draws a lot of amperage, which is what counts here, not watts. I would recommend installing a secondary fuse box to plug all of your toys into. You can buy genaric fuse blocks from auto parts stores. All you have to do is decide where you want to put it. If it is under the hood, then all of your accessories must have a wire going to it, which could lead to a lot of wire going through the firewall. If you put it inside, then you have a big wire with a lot of amperage at your immediate disposal. For that all you need to do is run one wire for the power to the battery. A common ground wouldn't be a bad idea to reduce the chances of static interferance from poor grounds. All of your toys will have thier own fuse in a centrally located place, and when you decide to add more stuff, all you have to do is add the new circuit to your fuse block. The trick here is to make sure that your supply wire from the battery is big enough to handle all of the accessories being on at once with a reserve. A safe rule of thumb would be to add up the amperage draws of all of your accessories and then give it another 25%. Just add up the numbers on the fuses for everything and add 25%. There are charts available online or else where that will tell you how big of supply wire you will need. To get really cool, you could add a constant duty relay rated close to your peak demand into your supply wire to act as a circuit protect, and so you can turn everything off at once with one master switch. This is something you would want to do when you start the vehicle to protect everything from getting fried from magnetic flux fields that get generated when the starter is engaged.

 

I didn't know they sold fuse boxes like that. I never did AV wiring in a car, just all audio. I'm more of a Home Theater guy, so this is some good info. I may just do that. It would be nice to have all of my accesories going to one place, but I'll still keep the radar detector wired into the mirror. That thing doesn't use anything. It's wired to come on when I start the car anyway. I like your relay idea also. If you go over the amperage the relay allows, does the relay blow out and have to be replaced, or does it reset like a circuit breaker? I have a 25A relay on my light bar but it would never have that much going through it to burn it out.

I have had a helluva time finding a place to run a power cable through the firewall. I found an alternate method, which was basically for the relay switch for the lights, just using the positive lead taped to the chasis where the door hinge is using red duct tape. Believe it or not, you can't even see it. The tape is the exact shade of the paint ( I really lucked out ) so that was my temporary fix. I have always found little niches in the firewall to feed my power through in all of my other cars, but they really have the H3 firewall sealed I'm assuming to prevent water from seaping in.

Do you know any good places to run a 14 guage wire through the firewall? 16 would probably be fine for what I'm doing, but I really like your aux fuse box idea. I'll have to check that out at Pep Boys this weekend.

 

The relay will blow and you will have to replace it. You could put a fuse inline so it blows first to protect the relay, which may be a better idea for circuit protection. If you cant find a fuse block at an auto parts store, some place like Radio Shack should have them. Since we are only talking about one wire and not a bunch, one idea is to drill a hole. All you would need to do is drill a hole in a good location and put a grommet in it to protect the wire from the sharp edge of the hole. Silicon the wire and grommet to keep water out, and now you have a good supply of power coming into the vehicle. If you are concerned with rust around the hole, before you put the grommet in, dab some touch up paint on the bare metal surfaces and let it dry. My first choice before doing this is to look for existing grommets that you can force one more wire through, or rubber plugs in the fire wall that were installed at the factory to fill in unused access holes.

14 or 16 gauge wire might be a bit on the small side. Keep in mind, when you have everything on, there is a lot of power going through that wire. Those wire gauges would be fine for almost all of your accessories on an individual basis, but combined I doubt they will be big enough. You are probably going to be looking at something like a 12 gauge, but more realistically like a 10 gauge wire. I know for a fact that if you were to rewire your lights into the new fuse block a 14 or 16 gauge wire would not be sufficiant. Seriously though, be safe and make sure the wire you use is going to be sufficiant before you start. Too small of wire can lead to a fire, which would be a bad thing.

 

yup, get a power distribution block, pyramid,lightning audio,stinger all make good ones. Also run a big azz wire, I used zero gauge wire from the battery, make sure you put a fuse within 12" of the battery!! just run the zero gauge wire through the firewall and attach it to the distrabution block. Then you'll have 6-8 or more (depending on the size block you got) power outlets to wire anything you want. I used zero gauge cause I was running a system with over 6500 watts so I needed the extra juice, you can go smaller but I would keep it no smaller than 8 guage.

 

If he doesn't add anything more to what he has, a 10 gauge should be fine, but in your case you were drawing so much power you needed the biggest wire you could get. Your point about a stereo also adds someplace I forgot to mention as a source for an auxillary fuse block, stereo instalation shops. My delimma for myself is where to put the block, and how many relays I want to use for stuff, and wether I want it to be switched with the key along with a master switch so one or the other must be on for the circuit to be hot, or if I just want it to be on when the master is on, or if I want the master to be hot only when the key is on. Lots of choices and combinations to be made!

 

I found this distribution block on the Crutchfield site. Looks like it will work. It costs $79.95 part #211CBR44A

 

Dont you guys think this is a little overkill for a 5.6" lcd monitor and a dvd/tv tuner that is made to work off a cigarette lighter?

 

I think actually you need to tow one of these for all the power you'll be needing

 

Is that a diesel backup generator?