O.K, I'm trying to install my back-up camera-Yes I'm still working on it. I have mounted it on the far left side of the dash next to the drivers side pillar. Now I need to power it. I just have no idea what wire to tap into. Any suggestions would be most welcome but please remember I am truley mechanically challanged so the easier it is to find and get to the wire/connection the better. Thanks so much in advance

 

Does it have to be wired to come on only when in reverse?

 

The electrical systems on an H3 are pretty intricate. You just can’t go splicing into wires. I would not. However what I would do is run a separate fuse block from the battery to run all my extras. But remember this block is always hot and does not shut off with the key you must turn everything of manually. Maybe some one else may have a better Idea but that is what I would do…good luck and happy hummering.

 

Isn't there both switched and always on 12V leads behind the stereo!? Why not tie in to those, it's easy enough plus it makes for a clean install. As far as the reverse only aspect, isn't there a wire off of the ODB2 port that would accomplish this!? Wish I had a wiring scheme of both the H2 and the H3 ...
I would definitely not go with the extra block ...Besides, with a couple of T connectors for those power leads and some electrical tape and presto, we got ourself a nice, easy, clean install with very little risk of getting screwed up.

 

give me 10 minutes, I'll get the wires you need

 

ok, look under the dash in the drivers side, you will see a plug near the bottom of the steering column (sp) Here is a picture of it. Use the wire in the pic marked acc. for your power, this will power the unit on when your truck is started (or key is in the on position) You can also use the black wire in the piture with the yellow end connector (screwed into the metal bar) as your ground. There is a reverse power wire under there in a big wire bundle that goes to the trailer plug (there if you have towing package or not) But you would have to test for that wire as I don't know off the top of my head which it is.

Wiring to the acc lead should be good enough as your camera monitor should have an on/off button on it that you can turn on only when you are in reverse or want to use the camera. If it doesn't just wire a simple two pole toggle switch to the wire going from your monitor to the acc lead, that way you just flip the switch when you want the camerea to turn on.

 

There's an even easier way!!!

If you look under your dashboard on the right side of the steering wheel, just behind the plastic molding where the center of the console is, you will see a harness of 3 or 4 wires with a tag that says "Aux Trailer Control" or "Trailer Brake", something to that effect. This is not used by the factory on the H3, but all of the wires are active. One is labelled "B+" which is a postive battery lead from the battery that is ALWAYS ON. You can use that for the main power since it's not used for anything, BUT it will always be active. Does your camera automatically turn on and off?

I use this wire for my AC/DC Power Inverter and it works great. It's a thicker guage then most other "Hot" wires under the dash, so it can handle a pretty good load.

 

why would he want a constant power? Even if the camera is an auto on off, all it takes is one malfunction of the unit and your going out to a dead battery. The harness in the pic is right below the one you are talking about and that acc wire is what you tap into for aftermarket alarms/auto starters so it won't have a problem bieng spliced into. Be careful when running aftermarket goodies to a constant power source...one faulty component inside the thing and your calling onstar for a jump.

 

Thanks Impy, that's more or less what I ment ... Now if someone has the wiring schematics for the under dash crap for the H2 and H3 and they are willing to supply it, PM me. They come in handy quite a bit!
I wouldn't share grounds though, have had some issues with that in the past!

I agree, switched 12V would provide a level of comfort knowing it won't drain the battery like the constant 12v would ...

 

sharing this ground wouldn't affect anything, it's not a main system ground and any interferance that could possible be produced will be very very minimal cause it's grounded to a main metal support brace, not to the body where you start to get into ground loop problems.

What wires do you need for your h2...I have all of em, just can't copy it cause they are protected or some crap like that.