hardcoreracing

I purchased a non-branded in dash lcd monitor for installing in my car. The install went fine, but when I tried to power it up, I got no power going to the unit. Here's how I hooked it up. There are four wires connected to a sata connector. Two of the wires say GND which I assumed meant ground. I grounded these to one of the monitor's mounting screws. Of the other two wires, one said ACC and was red, so I hooked this up to the same power wire as my aftermarket clarion head unit. The other wire said DC +12V. I hooked this wire up to the same memory yellow wire that my clarion unit was soldered to. Do these connections sound right? I'm getting no power at all from the lcd monitor, yet my clarion head unit works perfectly fine. Both are connected to the same power source. Any ideas?

MP3Car.com

 

davidp

try connecting the ground wire to a ground from the car, not the unit itself.

david

hardcoreracing

I connected both ground wires to the mounting screw holding in the side brackets of the monitor. Should I ground them to some other location? My clarion head unit also has a ground wire. Should I ground all three wires to the same location? Any other way to test the unit to make sure it's the unit and not the way I have it hooked up in the car? I was thinking of using a computer power supply, but would the sata connector pinout be the same as the power supply's pinouts?

davidp

i would connect all of the grounds to the same point, try to find a point that you know is going to be grounded well (a metal panel or something) make sure to scape ALL of the paint off of the surface to ensure a good connection.

if you want to test it, you can use an old power supply, on the molex connector for a drive, use the yellow and black wires (yellow is positive, black is ground)

hope this helps
david

hardcoreracing

I'm starting to think I connected the ACC and DC+12V wires to the wrong places meaning I switched them around. Seems weird since I connected red to red and yellow to yellow. Any danger in switching them around to see if that solves the problem?

davidp

there should be no real danger other than possibly running down your battery if the acc is hooked up to a constant 12v+.

the red should be the acc line, and yellow should be the constant 12v+, i think its pretty much universal with car electronics. if i were you i would just pull it out of the car and bench test it to make sure its actually working properly, then tackle the wiring issue.

david

hardcoreracing

Thanks for your help! Turns out it was the wiring that was switched around. I guess I shouldn't have looked at the colors. Plus what happens after I get it hooked up correctly is the clock is real dim, you can barely read it looking like it's not getting any power. When you push the power button on the unit, it doesn't do anything. Only by pushing the eject screen button do you see anything happen. The screen ejects out and the clock numbers get brighter. It's alive...

krnpimpsta

BTW.. "Ground" on DC devices does not mean the same as "Ground" on AC devices.

On AC devices, "Ground" is the 3rd prong, that is connected to the Chassis and Earth. Current should not flow through this connection in a perfectly designed system and this is only avoid a build up of charge.

On DC devices, such as 99% of your carputer gear and all car audio gear, "Ground" actually means "connected to the negative terminal of the battery." The reason why we call the car's chassis "ground," is because the car's chassis is connected to the negative terminal of the battery.

When you connect the ground wire to the chassis of the LCD, it is not connected to the negative terminal of the battery. That is why you need to connect it either to the CAR's chassis or directly to the battery.

MP3Car.com