Always on USB Power?

MrMagloo · May 15, 2023

Just finally got my 2023 RST 3.0L NHT. I have been searching for a solution to enable always on USB power and read about moving a 50a fuse on the passenger size fuse box. However, upon inspection, there are only 2 prongs in the F27 section, and there is no prong on the far end of the F28. So, it appears the default location of using the F27 position should provide power full time. And, the F28 position without a second prong I'm not sure what this would allow. I cannot tell any difference in either position, so it's a little confusing what is actually supposed to happen with these F27/28 positions.

Either way, in both positions, I get power to the USB ports, and after the car turns off, it appears I get power for a short period of time, but it eventually goes off. I'd like to find a way to keep the USB ports, or at least the ones on the dash always on.

Any tips? Fwiw, I'm running a V1 with JBV1 on a throw away phone that I leave in the vehicle full time. Thanks!

Edited May 15, 2023 by MrMagloo

redwngr · May 15, 2023

F26 USB Ports/Special Equipment option Retained Accessory Power

F27 Accessory Power Outlet/ Retained Accessory Power

F28 Accessory Power Outlet/ Battery

When on 'battery' the accessory power outlet should not shut off.

Perhaps get a power port/usb adapter to power your goodies

Be sure the draw will be low enough that it doesn't drain the battery - there have been lots of reports of items left plugged in that will drain the battery.

MrMagloo · May 15, 2023

Hi Red,

From what I think I understand, anything listed as RAP will run for a few minutes, then turn the power off. It appears that positioning the 50A fuse to the F27 location, which is the factory default, will enable RAP.

The F28 position did seem to be the full time battery option, but again, there is no second prong. That entire F27/28 elongated slot on 2022 and earlier models appear to have had 3 prongs coming up from the back of the fuse panel, and the center prong was used by both positions. Mine has prongs that cover F27 Left and Center, but position F28 only has Center, and the right prong is missing.

Has anyone looked into adding that far right prong, and how, and did that restore the full time power?

Thanks!

Edited May 15, 2023 by MrMagloo

2016 Sierra Owner · May 16, 2023

5 hours ago, MrMagloo said:

Hi Red,

From what I think I understand, anything listed as RAP will run for a few minutes, then turn the power off. It appears that positioning the 50A fuse to the F27 location, which is the factory default, will enable RAP.

The F28 position did seem to be the full time battery option, but again, there is no second prong. That entire F27/28 elongated slot on 2022 and earlier models appear to have had 3 prongs coming up from the back of the fuse panel, and the center prong was used by both positions. Mine has prongs that cover F27 Left and Center, but position F28 only has Center, and the right prong is missing.

Has anyone looked into adding that far right prong, and how, and did that restore the full time power?

Thanks!

It sounds like they did what RAM did with theirs. The are 3 slots. One tab goes in the middle and either makes the connection for F27 or flip the fuse for it to make the connection to F28. Skip to about 130 and you will see what I'm talking about.

MrMagloo · May 16, 2023

Hi 2016,

That was kind of the situation with the earlier models, with the exception that in the right passenger fuse compartment, there was a F27/28 slot that used to have three prongs and the 50a fuse was female. The outside prongs had power coming in. For F27 it was from RAP, meaning it was switched but would stay on after shutoff for a few minutes. In the F28 position, that outside prong was battery, meaning it was full time power.

However, the problem is, that outside F28 battery prong is not present anymore as with the earlier 19's through perhaps the 21's or 22's. In my 23 at least, there is only 2 prongs on the F27 position. That F28 BATT is blank.

So the question now is, has anyone tried to restore this F28 BATT prong, and if so, is there a part number and where was the BATT power sourced?

Thanks!

MrMagloo · May 16, 2023

Well as an update, I tried a test in running leads into the 50a fuse held remotely, by running one test lead to constant 12v, and the other test lead to the center prong of the F27/28. No joy.

I then removed the test leads and left the 50a fuse disconnected, and the USB ports were energized upon cycle.

It appears something else other than F27 is providing power to the USB ports, at least on the 23's.

Lastly on edit, I put everything back to stock, started the vehicle and confirmed the dash USB A was providing power. I removed the F26 and F27 fuse, and surprisingly I was still getting power.

Back to ground zero.

Edited May 16, 2023 by MrMagloo

redwngr · May 16, 2023

Something strange is going on.

The stuff I posted previously was cut and paste from the 2023 owners manual - for the instrument panel (right hand) fuse block.

(the other panels (left hand instrument panel & engine compartment) also use those fuse numbers....seems like a bad idea on GM's part...I'd think each fuse panel should use a different set of numbers, but they didn't call and ask for my opinion)

I think the right hand panel, F27/F28 thing is an either/or fuse.

The location selected (F27 or F28, instrument panel fuse block on(on passenger side) determines how the power outlet (not the usb's) will function.

Right hand panel has fuses on both side.

Here is a screen grab of the info from my prior post.

redwngr · May 16, 2023

1 hour ago, MrMagloo said:

Well as an update, I tried a test in running leads into the 50a fuse held remotely, by running one test lead to constant 12v, and the other test lead to the center prong of the F27/28. No joy.

I then removed the test leads and left the 50a fuse disconnected, and the USB ports were energized upon cycle.

It appears something else other than F27 is providing power to the USB ports, at least on the 23's.

Lastly on edit, I put everything back to stock, started the vehicle and confirmed the dash USB A was providing power. I removed the F26 and F27 fuse, and surprisingly I was still getting power.

Back to ground zero.

According to the manual, the USB is powered by F26, not by F27/F28 -- which are for the power outlet.

MrMagloo · May 16, 2023

Thanks Red, Yes still trying to sort this out and doing a lot of searching. It does seem that some of the earlier posts in 2019 thru 2021 referenced the USB and Power outlets were effected by F27/28. But to set that to rest, on my 2023 there are only prongs in the F27 position, far left and center. That F28 far right prong is missing so it appears they did away with full time power for the outlets at least.

Now what is confusing is, I started the truck, and connected a USB light to the USB-A Port in the dash and had power. Then I removed fuse F26. I was anticipating that the USB port would power down, but it didn't. Very strange.

At this point, I'm getting very close to just mounting a generical USB port under the dash to any full time power circuit I can find and calling it a day.

On Edit, with the truck running and the USB light connected to USB-A dash, as mentioned pulling F26 did not remove the power to the dash USB port. After trying a couple other safe fuses, when I pulled F32, the radio and the USB ports immediately died. Seems those dash ports are powered by the radio?

Perhaps the USB ports in the center console storage area and the back of the console are powered by F26?

Edited May 16, 2023 by MrMagloo

srwoolc · May 19, 2023

So, I have a 2021 AT4. I've not been through the manual and fuse blocks like y'all. Y'all have more energy than I...

However, the only thing I have found that retains power is the old 'cigarette lighter' connection. Everything else shuts down. One of the USB A ports retains power 'for a while'. I think it's about ten minutes (the same as the radio if you don't get out of the vehicle)

Don't know if the newer model years have that connection or not, but for me that still works

That port is also the only thing strong enough to power an AC/DC converter to run a laptop computer.

MrMagloo · May 19, 2023

I'm not sure I've seen an "old cigarette lighter connection" in a 2023. As discussed earlier, the F27/28 appears to be that circuit, but that doesn't have the full time Batt prong in the F28 position anymore. Probably because there is no Cigar Sockets on the 2023's.

redwngr · May 19, 2023

I'm not sure if todays 12V Power port can operate a cigarette lighter port, but it will power devices like radar detectors that have a similar style of plug.

Lots of makers/suppliers of Including usb adapters that can be used to charge devices from one of these ports.

Work truck should have the layout of the previous gen

USB-C, USB-A, 12V power port (highlighted in this OM diagram) and then the 120V port

Higher trim, the power port is in the console:

MrMagloo · May 22, 2023

2023's don't have a cigar lighter port anywhere in the vehicle.

redwngr · May 22, 2023

5 hours ago, MrMagloo said:

2023's don't have a cigar lighter port anywhere in the vehicle.

Are you saying 2023's have no '12V power outlet' or 'no cigar lighter'?

(ya, I get that the power ports are sometimes (incorrectly) referred to as cigar/cigarette lighters)

Diagrams posted were from the 2023 1500 Sierra Owners Manual...

Didn't check for 12v outlets in the one I test drove.

Edited May 22, 2023 by redwngr

MrMagloo · May 22, 2023

There are no Cigar type 12v outlets anywhere on the truck. I do realize there is a very subtle difference in that the Cigar outlet will retain the heating element whereas the 12v port will not, but there is none of either configuration. You only get the USB-A and USB-C on the dash and in the console, and another set on the back of the console for the rear seat. You also get a 120V outlet in the console and in the bed. No 12v Power or Cigar outlets. I was shocked myself. I know alot of people stopped smoking over the past few years, but how many trades guys driving pickups still smoke?