I'm a newbie with this month's dumbest question!

Tekmazter · 03-21-2005, 04:13 PM

Okay, I picked up a couple of 12V/DC headrest LCD's for my rear passengers similar to the pic below (The power/video cable is what I am most interested in asking about here)

The question: My wiring harness that came with each LCD plugs into the small DIN looking 3" cable coming out of the back of the LCD. Once plugged in, I then have one yellow plug (video) and another black female plug (power) on the end which is supposed to go to the video source and power source. My question is , what kind of cable plugs into the female power source jack and could I then proceed to run this directly to say the fuse box?

Any links or pics would be beneficial ...thanks

hannibal · 03-21-2005, 04:55 PM

it may just be a female rca plug on the power cord.
Can the yellow plug fit into the black plug??

EsKALad · 03-21-2005, 05:08 PM

lets see a picture of the female power plug!

Tekmazter · 03-21-2005, 06:07 PM

Okay, I ran out to the local electrical shop with cable in hand and found that this would be called an 'M-Plug'. Anyway, they had a plug like this:

attached to a cigarette lighter adapter which could work in this case. However, I'm looking to run this directly to the battery, a distribution block or to the fuse box. I think you get the idea. Anyway, I am thinking about cutting off the adapter but I am not sure which wire would be the positive and which one would be the negative. Basically the female jack is a round connector with a single pin in the middle. It looks similar to say a coax cable in form.

HostileJava · 03-21-2005, 06:49 PM

Whatever lead on the wire is going to the outside of the connector is usually neg and the center is usually pos.

Tekmazter · 03-21-2005, 07:42 PM

Quote: Originally Posted by HostileJava

Whatever lead on the wire is going to the outside of the connector is usually neg and the center is usually pos.

Hey HostileJava,

Thank you for that reply. Is there anything I need to worry about running it directly to the battery or via a power wire? The LCD is 12v/DC so I know I'm ok there, but someone mentioned something about needing to get the polarity before doing this, but I was under the impression that determining which wire is positive and which one is negative would be the same thing. Am I right in assuming this or am I misunderstanding polarity? Been a looooong time since I've done anything electrical.

shizzle · 03-22-2005, 09:27 AM

I am assuming you are building a carputer? In this case you would need something to handle the amperage; those wouldnt last more than a few seconds, either way. You would run a single power line to the battery. If it is going to handle all you power needs, 8 guage wire is a minimum... 4 is what I hear most people using now. I used 8 back in the day for a 300 watt audio system and it was fine, with a 20A fuse. It didnt last but ten minutes with a 15A fuse. I went through three 15A fuses. Im still a n00b, dont be discouraged.

shizzle · 03-22-2005, 09:29 AM

der_soldat · 03-23-2005, 11:51 AM

It's a monitor, not a 300W amp. I'm sure it will work fine on pretty narrow wire.

Just make sure not to install it to a circuit that will not be on when the car is off, or you'll drain your battery.

shizzle · 03-27-2005, 11:26 PM

Quote: Originally Posted by der_soldat

It's a monitor, not a 300W amp. I'm sure it will work fine on pretty narrow wire.

I was just covering bases... if the "video source" needs power too, might as well run his own fused circuit.

Quote: Originally Posted by der_soldat

Just make sure not to install it to a circuit that will not be on when the car is off, or you'll drain your battery.

I assume you mean TO NOT install it to a circuit that WILL be on when the car is off...

But yea, if you just need to power them little lcds, no prob.
a carputer is a little trickier.