Adding power ports & switches, on my GMT800 Suburban

[rayra]

Been a few general electrical Q&As lately and I was on the cusp of this work anyway, so I figured I'd document it somewhat. And it doesn't quite rise to the 'power system' nature of our other subforum, so I put it here in General Mods.
I'm in the middle of making several small tweaks and additions to my Sub, for a variety of uses. Overall I'm trying to keep the changes low-key, make things blend in with the factory look as much as possible, while still adding capabilities.
I'll also be adding lights in front, top and rear, as well as CB and HAM radios. All on new circuits and using dash switches and relays. The work in this topic is being spliced into / added to the existing factory wiring, as the loads are small and an expansion of features already in the vehicle.

Here's the stuff I did today -


First it was some troubleshooting and fuse replacement, to get my cig lighter / power port sockets functional again. Then I got to work enlarging a hole in the rear 'D' pillar by the hatch, where a factory door lock button is located, to make room for the switches I was adding for the LED light strings (mentioned and pictured in previous topics, I've rimmed the rear hatch with LED light strips. I'm altering that and adding both white and red lights to serve different purposes).

Having too many hobbies over the years, I have a few plastic shoeboxes full of spare wiring, switches, micro fans, etc, material cadged from long years of building and cannibalizing small electronics and PCs. I used a couple external hard drive / CD power switches, much more confident in those than the recent cheap chicom crap I bought and put in the dash. I originally planned to put a switch on each side, driver side for the white LEDs, passenger side for the red, so they wouldn't get mixed up. But there's no hole there and didn't want to be chopping stuff up twice, or messing with the other wiring or dismantling much of the rear trim just to get to that spot over and over (still don't have the 'final' LED strips in hand, yet.
So instead I re-worked the power and ground taps I'd done months ago on the rear power port (always hot) and extended that power and ground to the rear lock location AND split it into two ends each, to provide both power and ground to each of the new switches. When I add the LED strips later I'll rig them to the switches and be done. The rearmost switch will be red, an easy mnemonic, rear/red.

Then it was on to adding a USB power connection in the front upper console. That console's a bit crowded, as it holds rear A/C controls, garage door opener, sunroof control switch and two independent interior lamps and their switches. And the mounting brackets / metal clips that hold the console also intrude into the console.
I was intending to use a small dual USB plug cig lighter insert that I had, for its small size. I planned to do some surgery on it, add some wire leads which I could splice into the interior lamp circuit (also always hot). But after cutting that insert open and preparing to solder some wires in it, I changed my mind. I have a couple boat / RV -style dual USB power ports inbound (slow plane from China) which have higher amp ratings than the flimsy thing I was chopping up. And in fully removing and disconnecting all the wiring harnesses in the upper console I got a better appreciation of the spaces available. And I already possessed an boat/RV style 12v port. Seeing I could fit it down in the foremost portion of the console, I elected to integrate it instead. And transfer the dash USB adapter I currently use to its location for the interim. That 12v port is the same barrel shape as the inbound adapter, it will be a simple swap when it arrives.
So I identified the various plugs and splits in the console, identified the power and ground leads I wanted to tie into and did so, adding 'normal' red & black wires for my work and spade connectors on their ends.

Then I got it all back together and started fiddling with layout and too-long USB cables. I need to shop for some short cabling, once I decide where everything is staying. It's a random mess of standards. My old iPhone 4s uses the old 30pin connection, and I power it already with a dual-use USB cable which has a normal / current skinny micro-USB connector on the equipment end, and a 30pin adapter that's leashed to it. The new dashcam uses the old / original / fat 'mini'-USB connection on the equipment end.
Then there's the Samsung 7" tablet, which uses a micro-USB.

With multiple apps and traffic updates going on the phone, it needs more than 1A to maintain its battery level. Likewise the tablet when both bluetooth and GPS are enabled. The camera only came with a 1A cig lighter cord (in addition to other cables), so it's safe to assume a 1A source will do for it.

The factory aux power / power port circuit is fused at 20A and powers the rightmost dash port, the port on the rear of the front center console and the port at the rear of the cargo bay. And now also my rear hatch LED light strings and soon another USB port inside the center console. The factory cig lighter (and middle power port) circuit and the interior courtesy light circuit (which also powers the garage door opener) are both fused at 15A. So I'm fairly confident I can 'get away with' adding on these other loads without coming near any limits of wire gauge or fuses.

And my future heavier electrical loads will be connected to entirely new and aptly sized circuits.

 

[Weeds]

Thanks for the write-up!

 

[Burb One]

Looks great!

Interesting, I don't have that rear lock button... That was stock?

I wonder if the wiring is there and I can add it...

 

[rayra]

Yep. Don't know if maybe it's LT or LTZ trim accessory. Pull that D-pillar cover loose and you'll see the hole in the metal pillar and the plug for it if the harness includes it. If so all you need is the switch mechanism. I can take some measurements for the placement of the cut-out in the plastic panel for the switch.

 

[Burb One]

I dont remember seeing anything the last time I had it off, but I will put this on my list and good to know such a switch exists. With sleeping in the rear, will make it easy to lock/unlock the doors without fumbling to the front seat or finding the fob....

 

[rayra]

Yep. But what is really needed is an inside means of opening the rear hatch. Or glass. I seem to recall the older Subs having a handle on the inside. OR maybe I'm remembering an old station wagon.

I also took down the top rear trim while I was stripping my previous LED strip install and putting the interior back together, pulled down the rear headliner trying to get a look and didn't see anything like the thick rag insulation under the carpet. There seems to be a 1/4" layer of open cell foam, topped with a layer of material that looks like a cotton t-shirt. This sandwiched to the shaped / pressed fibrous material that is the headliner itself. But I didn't get a good view into the larger central 'field' of the headliner.

I'll get to my other ceiling projects in the next couple months, and really go for the full headliner takedown.

 

[Martinjmpr]

Since there's no handle on the inside of the liftgate, what is the purpose of the lock button on the D-pillar?
.
Dumb question: On the barn-door models, is there an inside handle? I would assume there is but I've never looked so I'm not sure. If there is an inside handle on the barn door models then can I assume that the lock was for the Suburban/Tahoes with barn doors only?

 

[rayra]

The switch has been handy when unloading the vehicle, when I've put away the keys and taken up stuff for the beach, or a hike or whatever, hit the lock, close the hatch, you're done.
I presume it's mostly for soccer moms / grocery getting.

 

[boll_rig]

Rayra, I just cut a small 2 in by 2 in square in my rear door panel to access the level that opens the door so I can get out from the back. Ill try and put up a photo when I take one, as well as updating my building thread with these sorts of thing. Its nothing fancy, but if you can get over a small hole, and it not looking exactly in place then it works just fine.

Also fine work indeed on the usb port and the accessories mounted up there!

-edit-
heres the photo I just took of the hole



I just use my left pointer finger to grab the lever and it opens right up.

 

[rayra]

thanks, that's something to look for on the lift gate Subs. Got to be a bar or pivot that can be extended or attached to, such that some sort of handle can be mounted on the inside end. Something else to look into.

 

[rayra]

Got my USB power port for the upper console. It looks near identical to those sold on Powerwerx for $19, but I got it via amazon for $7. So I figured it was worth buying one to see how it holds up. If it works well enough I'll get three more for other locations (inside the center console, and both ends of my 'power module'.

I'll wait for my short USB cable order to come (from Monoprice), before I mess with installing it. Should be a straight swap for the cig lighter port I put in earlier.

And a note on that, I've had the USB plug-in adapter come loose several times on bumpy roads, from that overhead port location. The cig lighter port is at a sharp downward-facing angle. And the spring-loaded center contact / plunger of the plug-in adapter is basically helping push it out. That adapter has worked fine in the horizontal position in the dash socket for over a year. and once this dedicated USB port is in place, there should be no disconnection issue.

 

[rayra]

It was a simple effort to swap the USB port for the previously installed cig lighter port. 2nd pic is a bad rear view mirror image.

I'm still experimenting with too many gadgets. Tryign different arrangements. Cellphone holder, dash cam, etc. And almost got my new double-din stereo / DVD player installed, but ran into a hangup with teh rest of the Bose system, need yet another adapter for everything to work. But I got the fitment done.

Also fiddling with the radio and center consoles, adding the USB port inside the center console and adding the wiring, figuring a fuse block location in the radio chassis that I can access by pulling the upholstered side piece off.

This is the underside of the center console, the lower arrow points to the factory power port / cig lighter socket on the back side of the console which faces the 2nd row seats. The upper arrow is the new USB port I added inside the console in the pre-molded location. I'll use it to keep my bluetooth earpiece and 7" tablet charged when they are stored / put away.

A closeup of that 2nd row socket, makes wiring identification real easy.

I used a wire stripping tool to split the insulation on the factory wiring run at a suitable place and added my new wires (in standard red / black color code) to run up to the new USB power port. Simplest way as the factory wire loom doesn't have very much slack at all in it. This way I don't shorten it at all.
I trimmed the projecting wires, taped them up individually and then taped things up again into a loom of sorts. Enough to control the wires and preclude any wear / a short.

more to come. Until it gets too ridiculous or I burn the truck down.

 

[PGW]

You can open the liftgate from the inside with no mods. From the inside, start right in the middle of the liftgate (at the 'hump') just below the glass. There is a seam (running horizontally) in the two trim panels (upper/lower) on the liftgate, you will be reaching up between this seam, the plastic panels have enough flexibility. To pop open the glass reach up in the very middle and with your fingers push up the latch. To open the liftgate, move over to the right about 3-4 inches from center and move a latch towards the left (pass side). Kind of hard to explain in words but if you try it out you should be able to get it. I saw this on a youtube video, I was thinking of adding some sort of inside release but apparently it is not necessary. I successfully did this on my 2003 Yukon XL. There were some minor trim differences over the years but I don't know if that will make a difference.

 

[rayra]

Thanks for the info, i'll look into that. I'd much prefer to fabricate an operating handle, something flattish that fits close to the interior. I'm thinking about adding a MOLLE panel to that part of the hatch, mounting a shovel, 1st aid kit and it would be even better to work the handles / levers into this panel in a way that they are accessible but sheltered in a way that they don't get triggered by accident.

 

[rayra]

Part of the wiring and adapting mess, getting a bit out of hand.


Got my aftermarket stereo install working (in my '02 Sub), sans any expensive adapter. The factory amp needs 12v on the pink wire on the factory aux (Tape / CD) loom, which also plugs in the back of the factory radio but ISN'T serviced by the normal aftermarket cable adapter. This applies 2000-2002 Subs and maybe also 2003-2006 NON Bose. But maybe Bose too. That power to pink wire tells the factory amp to turn on / accept line inputs from the four pairs of speaker inputs. I fed it from the blue/white wire on the pioneer radio harness.


Behold, the Tower of Power. Or Tower of Babel. Or horrific head-on accident in the making. Whichever you prefer.

From top to bottom:
iPhone
Dashcam
7" Samsung Android tablet with built in GPS and Bluetooth, runs offline nav apps and Torque app for vehicle data via a $15 bluetooth adapter on the OBDII port
Pioneer AVH-280bt head unit, hands free phone, USB and aux cable inputs, DVD / DIVX, bluetooth connectivity.
And to come, these are mockups
Kenwood 2M HAM radio
CB radio which will also have a PA speaker.


eta

I'm still experimenting with placement and mounting methods for the cellphone and dashcam. I want something more secure, less obtrusive. The suction cup mounts basically suck. Until they don't suck and then stuff comes crashing down.

the install of a double-din head unit in the '02 was facilitated by getting an in-dash subchassis and the dashboard bezel from an '03-06 Sub / Tahoe / Avalanche / Silverado. The install also requires some trimming of that chassis and its integral metal back brace in the earlier series trucks. The air controls relocate downward in the later-series chassis and the bezel takes a little judicious trimming to fit the ends of the air control section and either the bezel or the top of the ashtray needs to be cut for clearance.
I took out the obsolete analog OnStar controls from the lower right of my dash and replaced them with a switch panel. From which various lights will be controlled, via relays. And power to the radio stack in the lower center console, which has an added 120mm 12VDC computer fan built into it to blow cooler air on the bottoms of the radios. mostly-closed console, hot climes.

All kinds of electrical stuff being added. I'll burn this sucker down yet.