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Author Topic: Installing 12v Tv  (Read 697 times)

Paperboy326

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Installing 12v Tv
« on: February 14, 2018, 07:53:07 PM »
I found a pig tail in our bin and it's labeled "TV Interlock" meant to turn tv off when driving. I can't see the tv when driving and was wondering can I use this 12v source to power a 12v supersonic 24" tv for the kids? How many amps is it good for, I can't find a fuse labeled it.  Our main tv is half cover by a slide and only runs on 120v. And I would rather have them strapped in their car seats than laying in their bunks watching those TV's. Thanks

2011 Fleetwood bounder.
« Last Edit: February 14, 2018, 07:55:48 PM by Paperboy326 »

John From Detroit

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Re: Installing 12v Tv
« Reply #1 on: February 15, 2018, 08:56:26 AM »
NO, sorry you likely can not, Wire is HOT only when key is on. (either acc or engine) and thus will not power TV when you want to watch it. Sorry.
Nothing adds excitement like something that is none of your business
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Paperboy326

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Re: Installing 12v Tv
« Reply #2 on: February 15, 2018, 09:36:24 AM »
That's when we want it to work is going down the road. We will use the main tv when parked. I just don't know how many amps it's good for and how many I need for a 12v tv.

kdbgoat

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Re: Installing 12v Tv
« Reply #3 on: February 15, 2018, 09:38:01 AM »
I think John got it backward.
I know you believe you understand what you think I said,
But I am not sure you realize what you heard is not what I meant


2016 Leprechaun 319DS

Gary RV_Wizard

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Re: Installing 12v Tv
« Reply #4 on: February 15, 2018, 10:46:09 AM »
That is not intended as a power supply wire, so is almost surely very light gauge wire (low amps). The tv interlock is merely a voltage sense line and does not actually power the tv or anything else.  It is conceivable it has no fuse at all, but more likely it is tapped off some other fused dash board circuit that is active only when the ignition is on.

Since your coach apparently does not have a tv interlock installed, it is possible that the interlock sense wire is not connected at either end.  RV builders use a common wiring harness for multiple models and simply leave unneeded wires dangling (as you can see).
Gary
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Paperboy326

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Re: Installing 12v Tv
« Reply #5 on: February 15, 2018, 10:56:01 AM »
Gotcha. It's hooked up I get 12v when the key is on. It's a 14awg wire. And goes down under the hood to a relay. But after that no idea where it's feed from.

Gary RV_Wizard

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Re: Installing 12v Tv
« Reply #6 on: February 15, 2018, 12:19:16 PM »
 14 gauge?  WOW! That would imply they expected up to a 15A load, but it may simply be teed off a circuit fused for that capacity so they used the same wire size to assure it meets code.  It's anybody's guess whether that circuit is already heavily loaded or whether you can pull several more amps from it.  A 12v tv can draw anywhere from 2 to maybe 7 amps, depending on screen size and audio system. 2-3A is probably typical but a 24" model is probably greater than that.

The relay is probably just the auxiliary "ignition on" power source.  The ignition key itself no longer switches much power - the amp loads are too high in modern vehicles. The ignition switch typically just engages relays for each switch position (ACC, ON, START).
Gary
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Paperboy326

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Re: Installing 12v Tv
« Reply #7 on: February 15, 2018, 02:43:09 PM »
I'll put the test light on it and start pulling fuses and see what it's tied into. Depending on that maybe I could install a in line fuse @ 3-4a so it blows before the main fuse. Or just use the wire since it's already fished up there and tap it's on to a spare spot in the fuse box.

Gary RV_Wizard

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Re: Installing 12v Tv
« Reply #8 on: February 16, 2018, 09:22:49 AM »
Note that you are probably looking for a chassis circuit fuse, not a house 12v circuit.
Gary
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Lou Schneider

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Re: Installing 12v Tv
« Reply #9 on: February 16, 2018, 01:08:14 PM »
I think people are over thinking this.  A 24 inch LED TV uses about 18 watts, or 1.5 amps at 12 volts, the same amount of power as an incandescent 12 volt light bulb.  That's not much power.

If the 14 gauge wire has power when you want it, go ahead and use it.  The LED TV doesn't use enough power to worry about.
« Last Edit: February 16, 2018, 01:24:22 PM by Lou Schneider »

Paperboy326

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Re: Installing 12v Tv
« Reply #10 on: February 16, 2018, 07:10:45 PM »
I ended up just taking the wire out of the relay and putting it to a spare fuse in the box. And the main reason was not knowing what fed the relay as is. I didn't want to blow a fuse while driving and lose power to who knows what.

Gary RV_Wizard

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Re: Installing 12v Tv
« Reply #11 on: February 17, 2018, 08:02:26 AM »
Quote
A 24 inch LED TV uses about 18 watts, or 1.5 amps at 12 volts, the same amount of power as an incandescent 12 volt light bulb.

I know that is true for a 16-17" LCD/Led tv, but I thought the larger sizes were somewhat more. Still not much, though. Even if it's 30W, not a big deal.

Update: I looked up a Samsung 24" smart Led tv and the Energy Star estimate shows about 22 watts, so still under 2A @ 12v.
Gary
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