Easy, switched, 12V Power and Ground!

[avusblue]

I cannot take credit for this, I found it on another forum oriented towards the GM pickup trucks. But here is an easy way to add accessory power that comes on and off with your ignition key. The terminals are hidden behind a cover in our drivers side footwell. This is retained accessory power -- "RAP" -- it comes on when you power up the vehicle, and stays on until you open the door, just like the radio.

Here's the thread I found it in:

If you look under the driver's side dash between the brake pedal and parking brake, you'll see the fuse/relay box (it's about 6" x 10" and has a smooth black plastic cover, just like on the GMT-900's). Pry the clasps on each side to remove. On my SLT there are three main banks, left to right, with the first being unoccupied (see attached pic). The slots within first bank are labeled 1-20, though only 11 actually have male connectors. I used my tester to determine the following: #'s 7 & 17 are constant 12v power [always on], #'s 10 & 11 are grounds, and #8 is the RAP [retained accessory power] ignition signal wire (again, see attached pic)

For newbies, RAP powers on with the key rotated to the first position and remains on until the ignition is turned completely off AND the driver's door is opened, just like the factory radio.

Enjoy!​

Here's a pic. On my 2015 Tahoe LT, it looks and works exactly as stated. Your mileage may vary!



Cheers, and good luck,

Dave.

 

[ezdaar]

awesome! tons of gizmos can utilize those terminals.
That #8 could run a relay bank if one needed a few switched hookups.

 

[Bueker]

Great info. Wouldn't by chance has the same details for an '08 Tahoe would ya?

 

[toleafs]

I cannot take credit for this, I found it on another forum oriented towards the GM pickup trucks. But here is an easy way to add accessory power that comes on and off with your ignition key. The terminals are hidden behind a cover in our drivers side footwell. This is retained accessory power -- "RAP" -- it comes on when you power up the vehicle, and stays on until you open the door, just like the radio.

Here's the thread I found it in:

If you look under the driver's side dash between the brake pedal and parking brake, you'll see the fuse/relay box (it's about 6" x 10" and has a smooth black plastic cover, just like on the GMT-900's). Pry the clasps on each side to remove. On my SLT there are three main banks, left to right, with the first being unoccupied (see attached pic). The slots within first bank are labeled 1-20, though only 11 actually have male connectors. I used my tester to determine the following: #'s 7 & 17 are constant 12v power [always on], #'s 10 & 11 are grounds, and #8 is the RAP [retained accessory power] ignition signal wire (again, see attached pic)

For newbies, RAP powers on with the key rotated to the first position and remains on until the ignition is turned completely off AND the driver's door is opened, just like the factory radio.

Enjoy!​

Here's a pic. On my 2015 Tahoe LT, it looks and works exactly as stated. Your mileage may vary!



Cheers, and good luck,

Dave.

Forgive me for asking a stupid question as I have only very basic skills on auto electrical. How do I tap into #8 and #10 pins in an empty bank. Do I need to buy a 20 pin harness??? I assume there is a basic generic one I can pick up at AZ or NAP?

 

[ezdaar]

Female spade

use a relay bank and you can use that one ING trigger to turn on or off multiple circuits, with overloading the OEM circuit.

Spoiler: Single relay board

Spoiler: duel relay bank

 

[Eldiablo]

I cannot take credit for this, I found it on another forum oriented towards the GM pickup trucks. But here is an easy way to add accessory power that comes on and off with your ignition key. The terminals are hidden behind a cover in our drivers side footwell. This is retained accessory power -- "RAP" -- it comes on when you power up the vehicle, and stays on until you open the door, just like the radio.

Here's the thread I found it in:

If you look under the driver's side dash between the brake pedal and parking brake, you'll see the fuse/relay box (it's about 6" x 10" and has a smooth black plastic cover, just like on the GMT-900's). Pry the clasps on each side to remove. On my SLT there are three main banks, left to right, with the first being unoccupied (see attached pic). The slots within first bank are labeled 1-20, though only 11 actually have male connectors. I used my tester to determine the following: #'s 7 & 17 are constant 12v power [always on], #'s 10 & 11 are grounds, and #8 is the RAP [retained accessory power] ignition signal wire (again, see attached pic)​

​

For newbies, RAP powers on with the key rotated to the first position and remains on until the ignition is turned completely off AND the driver's door is opened, just like the factory radio.​

​

Enjoy!​

Here's a pic. On my 2015 Tahoe LT, it looks and works exactly as stated. Your mileage may vary!

View attachment 158441

Cheers, and good luck,

Dave.

Here is a tip guys. Pull up the plastic schroud for the fuse box under the hood look to the right straight down whala brownh wire. Check it with you volt meter and hook it up easy peasy. I dont like messing around under the dash if I dont have to. Old knees in such and its much cleaner and your on the other side of the fuse.

 

[TMNcaddy]

Thanks!

 

[greenhornet]

I checked out my 2015 Tahoe LS and the terminals you have shown do not have any power.I found power + and - on terminals 10 and 11 that are live when key is on and that is with the switched relay under the left dash fuse panel to activate constant power with key off. This a great place for power you have found and not having to use the under hood fuse box.Thanks for the tip.

 

[Doubeleive]

I checked out my 2015 Tahoe LS and the terminals you have shown do not have any power.I found power + and - on terminals 10 and 11 that are live when key is on and that is with the switched relay under the left dash fuse panel to activate constant power with key off. This a great place for power you have found and not having to use the under hood fuse box.Thanks for the tip.

the terminals referenced in the initial post are RAP (retained accessory power) that being said those terminals will only have power with the key on, or with key removed and drivers door still closed and will have power for 10 minutes after key removal or until drivers door is opened.
It should also be noted that depending on the vehicle trim level that open terminal may be occupied with other accessory equipment in the vehicle, such as a ltz, denali, escalade.

 

[greenhornet]

AS mentioned I checked the power with no key.0 with key on and door open #10 was neg. *** 11 was battery voltage.What ever the outcome it is a good place for alternate power source.Thanks for the idea to use this access point.