Where are you tying in for auxilary power stuff?

Discussion in 'GM Electrical Tech' started by steved, May 6, 2012.

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  1. steved

    steved Former Member 100 Posts

    Where are you tying in for auxiliary stuff like lights, radios, and the like on something as new as a 2012? I see what appear to be two fused "auxiliary lugs" off the power distribution panel under the hood? I'm trying to avoid cutting into any factory wiring...

    What about an source for "ignition on" signal that I can run a relay with? If I can get hold of an "ignition on" signal, I can pull from the battery and trigger things through a relay using the signal source.

    Thoughts?
  2. stewart7225

    stewart7225 New Member

    Title says NBS but it actually is for the NNBS pickups. Not sure about the 2012's but i have the parts ordered and will hopefully be doing this to my 2008 later this week.

    http://www.gm-trucks.com/forums/index.php?showtopic=109163

    As far as the two lugs off the fusebox. One (i think the larger one) is for a brake controller. The other is a constant on 12 volt (have to put a 40 amp fuse in before you get power off the lug, its meant to provide power through 7 pin plug for a camper)
  3. steved

    steved Former Member 100 Posts

    Cool, thanks for the link.

    I'm probably going to stop by the dealer and talk with the service guy, find out if there is anything I need to know. I'm wondering if I already have some of the wiring in place because of the plow prep package? Supposedly some wiring ran fore and aft, plus the beacon wiring/switch.

    I also need to ask them where the camper wiring is located under bed...the $35 add-on for an in-bed wiring harness. I like to use the trailer wiring for auxiliary lighting because its fused separate of the truck's wiring.
  4. 08_rado_rocker

    08_rado_rocker New Member 100 Posts

    sounds like you've got it kinda figured out, but i was gonna say that on my 08, up behind and to the left of the brake pedal, theres a distribution block with a plastic cover on it. Not really sure what they're used for (possible iTBC plug-in) but i found a switched source that turns on w the key and shuts off when the ignition is killed and then door opened. I used an 18 gauge female end of a flat quick-connect terminal, cut half of it off and just used one side of it to slide onto the pin, I did the same as you're thinking and just used it as signal wire for a relay, which now runs my interior lighting (led strips under the dash and under the rear of the front seats) and also my amplifier power switch.

    edit: I lied, i forgot i actually moved the power source for my lighting to the yellow wire coming from the dimmer switch so they would dim with the dash lights and such. they were ridiculously bright and actually decreased visibility to outside at night haha.
    Last edited: May 7, 2012
  5. SurrealOne

    SurrealOne Former Member 1000 Posts 100 Posts

    On my 04 NBS truck I tap the IGN fuse for key/switched 12v.
  6. steved

    steved Former Member 100 Posts

    OK, reviewed the fuse panel diagrams in the OM and noticed there are several "SEO/upfitter" slots...Dodge had a "Body Builders Manual" that explained what all those circuits were and what the intended use was for. Does GM have anything explaining those extra slots?
  7. 08_rado_rocker

    08_rado_rocker New Member 100 Posts

    I've got a buddy who was a tech for GM there in Midland for over a year, I'll ask him later when I call him about getting an RPO list on my new toy if he can also figure out if that's what the spots i was talking about actually are. And if so, then I'll see if i cant get a technicians diagram for it off their employee logins.
  8. steved

    steved Former Member 100 Posts

  9. 08_rado_rocker

    08_rado_rocker New Member 100 Posts

    I personally went through with my fluke meter on the fuse block on the NNBS truck (my 08 at least) and every fuse in that panel is constant +12vdc. Was weird to me that they did this, as personally its my first time seeing one like that (I dont mess with other types of vehicles very often anymore so i bet there's more like this somewhere lol). I'm sure someone else has found otherwise somewhere else on the trucks, but even a buddy of mine who works as an installer for best buy said we might have to tie into something coming off the BCM for a switched 12vdc source to ignition. We searched for close to two hours before i found that slot i found behind the brake pedal.

    ---------- Post added at 07:45 AM ---------- Previous post was at 07:38 AM ----------

    Dang, how in the world did you find that haha. I guess i just suck using search engines, cause i can NEVER find stuff like that when I need it!

    ---------- Post added at 07:48 AM ---------- Previous post was at 07:45 AM ----------

    We should get an admin to sticky this thread or at least the post with the pdf link on it, as I'm sure this has been brought up before now and that's the first time I've seen that file...
  10. tbplus10

    tbplus10 Super Moderator Staff Member Platinum Contributor 1000 Posts 100 Posts

    On my 2011 I installed two fuse blocks under the hood to add power accesories through.
    I used Marine rated power distribution/fuse panels each with 6 open slots, one I ran directly from the battery and the other is run through a relay thats switched by the ign.
    So far I've only added an underhood light and back-up lights to the direct battery source and a CB to the switched source.
    I bought all my connectors and power blocks from Marine West.

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