Can I wire in dash cam from double power source?

[Rayyy]

I’d like the dash cam to turn on automatically when I turn the key to ON, but would also like to be able to turn on the cam with the key out, using a rocker switched I installed.

My question is: could I tap into two different fuse locations in the fuse block, and wire them in tandem to the same power wire of the dash cam… so, if I turn the key, that fuse will power up the cam, otherwise if I hit the switch, the other (constantly powered) fuse will activate the dash cam?

Would it cause a problem to accidentally power on both simultaneously?

 

[B-train]

As long as both power and both grounds are together it shouldn't be an different than a parallel circuit. However, using the toggle switch to power it up will backfeed the key on circuit. Depending on what fuse you pull from, could possibly cause issues.

I'd probably just choose one or the other. You could also just make a pigtail that allows the 2 sources you mentioned, but can only choose one at a time.

Another idea to go with your original plan is to put a diode in line with the 12v key on circuit. Then you could use the switched one and not push 12v back to the other circuit.

 

[Rayyy]

As long as both power and both grounds are together it shouldn't be an different than a parallel circuit. However, using the toggle switch to power it up will backfeed the key on circuit. Depending on what fuse you pull from, could possibly cause issues.

I'd probably just choose one or the other. You could also just make a pigtail that allows the 2 sources you mentioned, but can only choose one at a time.

Another idea to go with your original plan is to put a diode in line with the 12v key on circuit. Then you could use the switched one and not push 12v back to the other circuit.

Ahh okay, could I place a diode on each line before the merge just to be sure there’s no backfeed to either fuse?

 

[B-train]

Yes. I think that would do it and keep both separated

 

[MassHoe04]

I just installed a Boss Audio radio head unit and Boyo backup cam from Crutchfield. I used their Ready Harness service, where they made up the plug and play harness to plug the new radio in to the factory harness. Worth the $25!

Anyway, in the process of consulting with the Crutchfield tech, I found out the factory harness has a wire already in the connector that carries a reverse trigger signal from the BCM. There was no need to tap into reverse wires in my tail light assembly or on the tow hitch wiring harness. One of the pins in the factory harness connector for the radio carried the reverse trigger signal.

The Boss Audio head unit also had a wire on the back of the radio marked "Rear Cam PWR 12V+". That was a constant 12v+ feed that was live when ignition is in ACC or run mode. It goes live when the radio is powered on.

This simplified hooking up the backup cam.

With the 12V+ wire for the rear cam on the radio, that allowed the cam to be powered on and viewed without having being in R on the transmission. That is handy for checking on a trailer/load any time you need.
The reverse trigger signal from the radio harness still tells the radio head unit I am backing up and will throw the camera on the screen as soon as you shift to R.

Plug-in harness at the cam. Find a single body/chassis ground in the back. Connect the rear cam 12v+ on the back of the radio to the red wire on the camera harness. Connect video feed RCA jack. Snap in plug and play Ready Harness between truck harness and back of radio head unit.

I am sure Crutchfield tech should help you figure out how to get it the way you want it. Their tech and sales support are top-notch!
Get a few of the Qwik-Tap connectors. Connect multiple wires, no crimping, no soldering, very secure connection.

 

[MassHoe04]

In response to your original set-up question...

I would want to wire a relay (or relays) in with the switch, so that power can only come one way and go out one way.
I would want the power to come on with the toggle when the accessory power is on and the reverse trigger is off.
I think relays would make that happen for you.

 

[Doubeleive]

I’d like the dash cam to turn on automatically when I turn the key to ON, but would also like to be able to turn on the cam with the key out, using a rocker switched I installed.

My question is: could I tap into two different fuse locations in the fuse block, and wire them in tandem to the same power wire of the dash cam… so, if I turn the key, that fuse will power up the cam, otherwise if I hit the switch, the other (constantly powered) fuse will activate the dash cam?

Would it cause a problem to accidentally power on both simultaneously?

your question really does not make logical sense
If you install a toggle switch then as long as it is installed properly it is impossible to "accidentally" do anything
that is the whole purpose of installing a switch to begin with.
for instance
switch position 1: accessory power
switch position 2: constant power
the only thing that could accidentally happen is to leave the switch in position 2 and eventually drain the battery

 

[MassHoe04]

your question really does not make logical sense
If you install a toggle switch then as long as it is installed properly it is impossible to "accidentally" do anything
that is the whole purpose of installing a switch to begin with.
for instance
switch position 1: accessory power
switch position 2: constant power
the only thing that could accidentally happen is to leave the switch in position 2 and eventually drain the battery

Or... You can do it easier @Doubeleive 's way... LOL

 

[Rayyy]

Hmm indeed, wow ya that is a much better plan. I was going to repurpose the switch I had already installed for a different reason, which is just an on/off switch… Although, installing a three position switch makes much more sense, doh!

I guess ideally I wanted the accessory power to be automatic regardless of switch position when the key was ON, but the three switch sounds like the best solution after all.

Thanks.

 

[Rayyy]

@Doubeleive How would I wire that up in the fuse box??

The three position switch has three terminal pins.

So, accessory power to one pin, constant power to another terminal pin… Dash cam positive to the middle pin?

 

[Doubeleive]

@Doubeleive How would I wire that up in the fuse box??

The three position switch has three terminal pins.

So, accessory power to one pin, constant power to another terminal pin… What connects to the middle terminal pin?

View attachment 386841

I am not familiar with that particular switch but I would assume the center pin is output in which case the camera power lead would go there and the camera ground would go directly to the body
you may also want to put a 5a fuse on each power lead as a safety precaution

 

[Rayyy]

I am not familiar with that particular switch but I would assume the center pin is output in which case the camera power lead would go there and the camera ground would go directly to the body
you may also want to put a 5a fuse on each power lead as a safety precaution

Good call. I was thinking 10 amp fuses since my fuse block tap pigtails have a built in fuse slot, and was concerned that one of the positions on the switch is rated for only 6 amps, but I’ll swap those out for 5 amp instead.

Would that be okay?

 

[Doubeleive]

Good call. I was thinking 10 amp fuses since my fuse block tap pigtails have a built in fuse slot, and was concerned that one of the positions on the switch is rated for only 6 amps, but I’ll swap those out for 5 amp instead.

Would that be okay?

it depends on the draw from the camera which probably isn't much but if for some reason a 5a is not enough bump up to a 10a but I think 5a is probably more than enough

 

[BlaineBug]

In January 2022 I installed a hardwire kit for my dash camera, that uses both full time power source for the parking mode as well as a switched power source for normal mode. I used 2 fuse taps in the driver's side fuse panel. Been working fine since.

 

[ScottyBoy]

Ahh okay, could I place a diode on each line before the merge just to be sure there’s no backfeed to either fuse?

Yes, a pair of diodes would work perfectly in this scenario.

 

[BlaineBug]

What kind of a camera? Often times I've seen that cameras, if purchased with the HARDWIRE KIT, already have both full time power and ignition powered feeds available, even though the same camera will be incapable of doing as such when using the included cigarette plug adapter.

 

[Doubeleive]

What kind of a camera? Often times I've seen that cameras, if purchased with the HARDWIRE KIT, already have both full time power and ignition powered feeds available, even though the same camera will be incapable of doing as such when using the included cigarette plug adapter.

some camera's are designed like that for "parking mode" so it can record if it detects a impact while technically off, it automatically switches modes when the key is off.
mine is a kenwood drv-830 and ca-dr100 hardwire kit, nobody has them here they have to be ordered from the uk or japan
dashcam's are much more popular in other countries

 

[BlaineBug]

some camera's are designed like that for "parking mode" so it can record if it detects a impact while technically off, it automatically switches modes when the key is off.
mine is a kenwood drv-830 and ca-dr100 hardwire kit, nobody has them here they have to be ordered from the uk or japan
dashcam's are much more popular in other countries

I have the REDTIGER F7N with hardwire kit. Installed since January 2022.

 

[Rayyy]

What kind of a camera? Often times I've seen that cameras, if purchased with the HARDWIRE KIT, already have both full time power and ignition powered feeds available, even though the same camera will be incapable of doing as such when using the included cigarette plug adapter.

My cam is a Vantrue N2… I do have a hardwire kit fit it, and will look into whether it’s already designed that way. Good call.

 

[BlaineBug]

My cam is a Vantrue N2… I do have a hardwire kit fit it, and will look into whether it’s already designed that way. Good call.

Vantrue Hardwire Kit for S2/X4S/N4/N2S/E1/E2/E3/E1lite/N1 Pro(2023)/N2 Pro(2023)

Vantrue Hardwire Kit for S2/X4S/N4/N2S/E1/E2/E3/E1lite/N1 Pro(2023)/N2 Pro(2023) ,11.5ft Type C USB 12V 24V to 5V Dash Cam.

www.vantrue.net

This doesn't have 2 leads for both power sources, alludes to connecting to full time power for parking surveillance or switched if you don't want to use parking surveillance.

I don't really see the point in installing a 3 way switch at all. Just connect a switch from constant +12 volts and leave it at that. If you have a rocker switch for what reason would you need that switched ignition power source?