I'm about to embark on several electrical accessory installs this weekend and am just trying to get a handle on the best place(s) to tap into existing electrical.


I've noticed bits of info on this all over the forum, depending on what you're installing, but is there any single post that gives an overview?


I ask because I can think of junction/fuse boxes in at least 5 locations I'm aware of: driver side door jamb, passenger side door jamb, driver side under dash, fuse box under hood, connector junction under bed/frame rail on driver side at back of bed.


Has anyone seen a single post that gives an overview of all these locations (or more if more exist) on the 2500HD (CC 4x4 LLY), and when to use each (aside from phsyical location convenience)? If not, anyone care to take a shot at this?


Thanks.

Not really it's all about convience and need ,sorry ....


Best you could opt for is list what your trying to accomplish ....





Mac

Google gmupfitter and then look at that site for the .pdf file "2003 and beyond" or something along those lines. I have it at home but don't recall the exact location while I'm at work. It has a pretty good rundown of the 2003+ electrical system w/schematics.Edited by: Minn-Kota

As Mac said. What are you trying to install?

Dude I feel your pain. It appears over whelming at first ecspecially if you are they type who likes to do electrical work clean and correct. No half assing.


Theoretically all hook ups should be done via a factory style connecter via a relay. There are several empty conector sockets just weighting for this type of hookup. They already have the power and switch wired to the back of the juntion box, you just have to add the connector and wires out. Without factory conectors and schematics this method can be difficult.


As stated before GM upfitters has some info on this, It refers to the mbec box on the floor?


A real straight forward easy method is to buy a fuse tap and a relay from the local auto store. Plug in the fuse tap to the prexisting fuse of your choice and go straight to the after market relay. you can mount the relay under the hood on the large box. Then jus run out the correct wires to your battery and new accesorie. I have even sceen relay connectors with preinstalled leads about 15" long.


If you are after trailer power there is a good chance you already have a wire harness and just need to install the presupplied 40 amp fuse that is in the fuse box under the hood.


Hope this helps. Edited by: Bronco

Mackin/Max Power - I'm looking to install the following this weekend:
<UL>
<LI>Rear lights - I'd like to tie them into reverse lights and be able to also flick them on/off at will</LI>
<LI>Rear cargo lights in bed of truck - to be controlled by cargo light in cab</LI>
<LI>Air compressor - to be mounted in toolbox in bed - to be switched in cab</LI>
<LI>Power inverter - to be installed in cab</LI>[/list]

Max,


While your at it. I installed rear lights too that I control from in the cab, but I would like them to come on with the reverse lights too. If I pick up the light green wire at the back of the trailer plug, (i think thats the right color) and feed it to my extra reverse lights that should turn them on when the factory reverse lights come on.


My question is if I turn the reverse lights on from the switch in the cab, it should turn on my factory reverse lights too, since it will backfeed. So is there any thing past the factory lights that when backfed that could be damaged by not actually being in reverse, like a switch or selonoid in the tranny?


Or does it just end at a switch somewhere and it won't bother anything by being backfeed?


Thx, Max Power=(Mr. Electric)

dduffy,


In addition to GMuplifter, another good source for the information you're looking for is the GM Service Manuals - a 5 volume set available from www.helminc.com (http://www.helminc.com). They contain electrical schematics and the locations of connectors/fuse blocks you would be tapping into for your mods.


One handy way of tapping circuits is with a


Little-Fuse add-a-circuit (http://community.webshots.com/photo/77018086/143154203ZUDYIZ)


http://thumb3.webshots.com/s/thumb1/5/42/3/143154203ZUDYIZ_th.jpg


There is also a 30A fused accessory circuit (http://community.webshots.com/photo/77018086/78006348ldgpAd) in the under-hood fuse box that can be tapped for electrical mods.


http://www.dieselplace.com/forum/smileys/Geek.gif

If you use a relay to feed the power to the lights and hook the reverse lights and your switch power to the coil of the relay through diodes, you will not have any feedback issues. Look at www.the12volt.com (http://www.the12volt.com) and they have all kinds of wiring help and instructions on the basics.

Chris,


Thanks for posting the link to www.the12volt.com (http://www.the12volt.com) ! Cool site.http://www.dieselplace.com/forum/smileys/Cool.gif