Using the same Ground/ACC Line

**jdiazj1** · 03-20-2006, 05:36 PM

Hello, i am currently planning all my wiring for my carputer and was wondering if i could do this. this is my plan for wiring my car ...

battery->fuse->power distributor block->amp and psu

amp and psu->grounding block->vehicle chassis

i want to use a motorized lcd in my dash. my dash has a line for Ground, and ACC line from the radio that used to be in there. ok my question is can i connect the one ACC line from the dash to the motorized LCD, so a aftermarket HU, to the PSU and to the amp. It seams like it wouldn't be a problem because the ACC line does not really a big load to power something, its just to trigger the device to turn on. Same thing for the GROUND wire in my dash, can i ground the LCD, the slim drive dvd player, and the aftermarket radio to it do or do i need to make another grounding spot with a thicker gauge wire to it. thanks

**Dr Frag** · 03-24-2006, 02:30 PM

As long as you're using the ACC line just for a trigger you can connect it to any unit that needs it but I would not use it to power more than the standard head unit. As for ground there is usually a heavy ground wire in the console area for connection to HU and such. If you don't have one I would recommend adding one from a local chassis point up to the console area.

David

**jdiazj1** · 03-24-2006, 04:43 PM

Thanks for ur response, about using the same acc line to turn on multiple component. U said that i can connect a couple of components to the same line to 'trigger' them to turn on. you sure i dont need to add a relay or something because according to this

"Using a 30 amp SPDT relay, connect terminal #87 to constant 12 volts positive with a fuse rated to the sum of the additional accessories you've added and the components you need to turn on. (If you have two fans rated at 5 amps each and a neon light rated at 10 amps, you would use a 20 amp fuse plus 200 ma for each amplifier and processor.) Connect terminal #85 to ground, terminal #86 to the remote turn on lead from the head unit, and terminal #30 to each accessory with an appropriate fuse. A fuse (not shown) could also be used between the output of the relay (#30) and the remote turn on lead of the amplifiers and/or processors for extra precaution."

I need to do this instead, is this correct?

thanks

**Dr Frag** · 03-24-2006, 06:25 PM

Most people do not use a relay to SUPPLY power to amps, carputers, displays, etc. Usually you run a heavy wire directly from the battery to whatever divice you want to power, with a fuse close to the battery in case the wire shorts to the chassis. It will blow the fuse and prevent melting the wire and causing a fire. Now if all you are doing is using the acc wire to signal the devices (connecting it to the remote turn on terminal) then you can wire it up to whatever devices you need to since very little current is used to signal devices to turn on. There should be a wiring FAQ around here somewhere . . . A relay is not needed but some people like to use them to completely disconnect their electronics from the battery.