I'm planning to install a rear dash cam in my 2021 Yukon Denali and I'm looking for a source of power which will only be on when the ignition or Acc is on. I don't plan to use parking mode so I only need the two wire hardwire kit (GND/12V). Based on an earlier thread, the only switched fuse in the entire vehicle is in the Instrument Panel fuse box, F26 (USB/SEO RAP). Running a power wire the length of the vehicle to F26 is one option, but seems like a lot of work. There is a type C USB port close by. I assume there is some kind voltage converter module (12v to 5v) behind those ports which is fed with a 12 volt wire ? Could this be a viable source of power ? Would it be safe to tap it ? This USB port is part of the 10A circuit controlled by F26.
Looking to tap switched/Acc circuit for rear dash cam.
- Thread starter 01dailey
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BlaineBug
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Are you running a front camera or just a rear camera alone? Typically dash cameras are 5 volt and require a step down from 12 to 5. They are essentially a glorified USB web cam.
I already have a front camera and decided to get a rear one as well. Rather than getting the rear which goes with my front camera, the rear being a lower resolution extension that plugs into the main camera, I decided to go with an independent rear camera. You are correct, the dash cams operate on 5 volt. The hardwire harness kit contains a voltage converter (12v to 5v) which connects to the 12 volt system of the vehicle. The way I see it, I have two options here regarding the USB port. Simply plug into the USB port with USB cable (5v) and be done with it (not hard wire it), or hard wire it to the 12 volt wire feeding the USB port. The benefit being to not permanently occupy the port and to have the cable out of sight.
Please excuse my ignorance in my previous posts. The ports are connected with USB cable to a hub. There is no 12v source. I will have to either plug into the USB port or route my power from the Instrument Panel fuse box back to the rear of the vehicle.
BlaineBug
Full Access Member
I can't tell you which fuse(s) you can use in your rear fuse box, but a fuse tap may be the way to go. That's the way I installed my dash camera, with the rear camera that plugs in to the front camera. I tapped up front though. No cut factory wires or splices in my install.
There are no suitable fuses in the rear fuse box. Every fuse 20A and below has full time power, except for two (F12 & F49). These two have no power whether ignition is on or off. I'll tap F26 (USB/SEO RAP) in the front fuse box and route the cable to the rear.
I had quite an experience installing the front dash cam in my Yukon. I hard wired it using a fuse tap, but just couldn't get the camera to work. I then discovered there was no power at the camera end of the harness. I assumed that the voltage converter in the wiring harness (12v to 5v) must be defective. The next day the camera just came on by itself and worked fine, but only while the engine was running. I then discovered my battery was going bad. It won't charge up all the way and the in-harness converter was shutting off because the voltage was too low, as part of the battery protection. This week I'm getting a new battery.
WARNING: GMC strongly advises against using the OBD port to power devices of any kind.
BlaineBug
Full Access Member
What are the rear fuses without power?
Your only alternative is to run an extension wire from a switched source to the rear. My camera has parking mode too so it uses full time and switched power too.
Your only alternative is to run an extension wire from a switched source to the rear. My camera has parking mode too so it uses full time and switched power too.
I don't care about parking mode, so I only need switched power which is my F26 fuse in the forward fuse box.
The unpowered fuses I found in the rear box (only tested 20A and less) were F12 'GBS' (Glass Breakage Sensor) and F49 'Lift Glass' (Rear Hatch Glass Release ??). I measured these two fuses with ignition Acc off and on and there was no power. F12 is an alarm sensor so maybe the fuse is powered when the alarm is armed. I don't know about F49.
BlaineBug
Full Access Member
Do you know if there are any fuses back there for dome lights by chance? Off topic but since you've been back there and looked in to it. I've had the slight urge to add a cargo area dome light but really wouldn't want to go through the trouble of having to take down any other dome light in the vehicle as I hear they are a real bear to drop down from the headliner also often resulting in broken clips or brackets.
There are plenty of fuses you could tap, but all are full time power. You could have a dome light that switches manually. I think the ideal circuit to tap would be an empty fuse socket not in use. I think there may be some which are powered. My second choice would be to find a safe fuse to tap, and don't tap anything greater in amperage than the rating of the fuse tap.
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WalleyeMikeIII
Full Access Member
The Power Sliding Console is switched, I think?
Nope, it's not. The Sliding Console F38 has full time power.
BlaineBug
Full Access Member
Thank you and I hope not to clutter your post with nonsense. Did you know that the 2015, 2016 models had a 4th row cargo light, but then they eliminated it in 2017 or 2018? So the cargo area now relies on the 3rd row light to illuminate. I'd want a door switched power source if I was ever to add a cargo light. I guess I'll have to look into that further if that is what I want to do. Tapping off of the 3rd row dome light would seem to be ideal if it wasn't such a reported pain to pull down from the headliner and roofline.
TheGrayingTech
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Anyone ever use something like this:
Since the rear fuse panel is fully powered, I was considering putting a voltage protector between the fuse tap and the camera; In my case it is the iVolt battery system.
In theory, when the truck is off, voltage is too low so the switch turns off. When the truck is on, the voltage is high so the switch turns back on. Thus creating an ACC enabled circuit off of a constant source.
Since the rear fuse panel is fully powered, I was considering putting a voltage protector between the fuse tap and the camera; In my case it is the iVolt battery system.
In theory, when the truck is off, voltage is too low so the switch turns off. When the truck is on, the voltage is high so the switch turns back on. Thus creating an ACC enabled circuit off of a constant source.
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BlaineBug
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You may as well run a switched power source wire from the front to the rear. Less complication!
TheGrayingTech
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Maybe, but the passenger side compartment also does not have a 20a switched fuse. I only found 1 in the engine bay and that's more hassle to me.
BlaineBug
Full Access Member
It's not the most difficult thing to run a wire through a firewall grommet. Better than having to add yet another module! Also why in the world is this camera requiring 20 amps? I would think 5 would be sufficient.
PS - what are the factory accessory ports/cigarette lighter outlets fused at? I assume yours are switched power as are mine, and you can move over the fuse to make them full time power if you really wanted.
I'm looking for a RAP connection point on my 2021 Yukon Denali. Where ever the cigarette lighter socket is powered from would be perfect but I'm
not having any luck getting access to back of the socket. Does anyone know which fuse is powering the lighter socket?
One other point, what's with these 3 pin fuses? How do you tap off them and which pin?
not having any luck getting access to back of the socket. Does anyone know which fuse is powering the lighter socket?
One other point, what's with these 3 pin fuses? How do you tap off them and which pin?
jessiemartin2000
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Hello, I know this is from a long time ago, but what did you end up doing. I'm having the same issues.
I'm using a plug in fuse tap on F26 for the RAP connection to drive a relay under the hood providing battery power to my ham radio system. Works pretty well but I'm getting times when it powers down. If the vehicle is running and I open the drivers door the power cycles on F26. Likewise when I
pull to stop with auto engine stop enabled I get a power cycle on F26.
Using a cig plug with an LED on it I don't notice this problem with that feed.
Does anyone know an easy way to connect to the power that feeds the cig plug in the front center console? I have extended warranty and don't want
to do any cutting and soldering (yet).
pull to stop with auto engine stop enabled I get a power cycle on F26.
Using a cig plug with an LED on it I don't notice this problem with that feed.
Does anyone know an easy way to connect to the power that feeds the cig plug in the front center console? I have extended warranty and don't want
to do any cutting and soldering (yet).
