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Electronics expert help needed!! Backup cam install..

nghtrdr

Full Member
Joined
Jan 11, 2007
Messages
134
Location
GTA Ontario, Canada
Hi all,
I am currently working on the install of my backup cam setup. I would like to make a simply circuit board to switch 2 power sources to my cam and monitor (1. backup lights power, 2. switched power). Not sure if that sounds right so I will try to clarify.
I want to get power from two separate sources but want a circuit to switch from on to the other so I don?t send 24v to the cam or monitor. One source I want to get at the BCM from the backup lights source, the other I want ignition on a switch so I can have the cam and monitor on when I want. Say some moron driving like a mad man behind me on the highway.. This is all so there will be no mistakes in power switching as im not the only driver (the wife). Now I have heard this is possible using multiple relays. If this is true!  Is it safe?
I?m not new to a soldering iron and getting pn board is not a prob.
Please keep it simple though, I?m not an expert..

thnx
 
OK, I'm no expert, so take this for what it's worth... but if you had the vehicle in reverse (so the cam/monitor were on), and the "manual" switch was switched on, you would still only have 12V... not 24V... right?

Not sure which camera setup you are using, but I am pretty sure the cubbycam directions include instructions for wiring the system with a manual switch.

JHMO, but I can't see the value added in watching a crazy driver behind you. If they are that nuts, I'd be concentrating on looking in front of me to see where I can go to get out of his way. Given the size of the monitor, you aren't going to see much you can't see in your rear view mirror... and if they are close enough to only be seen in your back up cam, he is pretty darn close.

 
I am no expert either, but as for cubbycam which I yet to install, the instructions show to get the power from the cigarette lighter using a T-tap.
 
With the Cubby cam set up the power is supplied from the wire that runs to the reverse lights in the tail light housing. So whenever the truck is in reverse the camera & monitor come on. There is also a supplied over ride switch that is tapped into the cigarette lighter supply wire so you can turn on the camera & monitor anytime you want. There is a small diode in line with the wire from the tail light reverse light to prevent the reverse light from coming on when the over ride switch is in operation. Either way if the the over ride switch is on & the Av is put into reverse you will only supply the camera/ Monitor with 12 volts. The only way to get 24 volts from the Av is if you have a dual battery setup and they are some how wired in series. Most all 2 battery set ups are wired in parallel (+ to + and - to -) and supply? only 12 volts but have a longer run time than a single battery. When batteries are wired in series ( + to - , - to chassis and + to switches) they will supply 24 volts for about the same amount of time as a single battery ( But with the 24 volts you will more than likely burn up your electrical system) :badidea:.

Hope this helps
Ken
 
Where would the 24V come from?

Monitor operation is simply what you want it to slave to. (BackUp or ACC/RAP and/or ign.) that can directly switch your camera power or run to a small relay coil of which switches your camera source, if you have that wired to a back-up lamp source in the rear. That all depends on how you had wired it in the first place. You can just run a dedicated single wire to the camera, from the monitor power-selection switch, where it would switch power sources with the monitor - a simple SPDT switch. One pole of the switch connects to the BCM back-up lamp power, the other end to the Ign or other preferred source. Then just run the switched source to your cam & monitor. Fuse-protect your wiring!

Then maybe install a button for a pump to squirt mud onto the tailgater's front end. >:D
 
thnx Sperry for clearing that up for me with out all the condescending BS.
What size fuse would u recommend?

If u have two sources at 12v ea. going to one device, are u not giving double 12v x2 =24v to that device?
 
nghtrdr said:
thnx Sperry for clearing that up for me with out all the condescending BS.
What size fuse would u recommend?

If u have two sources at 12v ea. going to one device, are u not giving double 12v x2 =24v to that device?

You are corrrect two sources of 12v going to one device will not give you double voltage. The reason is because both sources are coming from the same point of origin.

PS: Sorry if my first post sounded condescending, just trying to help. (y)

Ken
 
:wave: You said you wanted simple, here goes, just hard wire the cam with a manual switch, either off or on!

Didit
 
nghtrdr said:
thnx Sperry for clearing that up for me with out all the condescending BS.
What size fuse would u recommend?

If u have two sources at 12v ea. going to one device, are u not giving double 12v x2 =24v to that device?

Double the current source capability maybe.. Stacking Voltage takes a different scheme than your connection.
You can stack independent power sources like cells or batteries of cells and the like to double, multiply or the like but just two connections to a common 12 Volt source won't do it.

That's speaking DC. AC can get well more complicated by far. :)

I highly recommend to anyone wanting to have a more clear understanding of this sort of thing, to take a course in DC theory, at least! You'll find it so helpful, you'll want to advance more yet with AC theory! :)

Now, if I could only tipe & spel bettur. :E:
 
A fuse is to protect the wire, more than the device(s).

A 5 Amp and 16 Gu wire should be plenty for both. Place the fuse as near as possible to the power source for the circuit. Did you read the power requirement (current draw) specs of the monitor? The camera?

There are so many variations of connection methods that the easiest way would be just copy something which works well for someone already, and to be certain of the wiring safety.
 
unfortunatly the cam or monitor did not come with any specs. so i do not know what the draw is for these devices!
i will start at 5amp fuse and go from there. i wired the truck with 14awg wire so im all set there. just need to do the taps at the bmc.

thnx for all the help and very informative posts..
 
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