Headless Setup - Quick Amp Wiring Question.

**crosseye** · 07-12-2004, 03:11 PM

I am removing the head unit from my car and adding a sub amp and 4ch amp to power my speakers. Right now, my PC is powered by a 300 watt inverter and a 150 watt PS. I am fully comfortable wiring the 12V and Ground connection to the amps, but since I do not have a head unit, I am unsure about what I should use for the 12V Remote signal to turn on the amp.

Can I use the 12V signal coming out of my PS so that when the PC is on, the amps are on? If I do that, do I need to tie the PS ground and the car battery ground together so both have the same reference points? Or is this bad because the PS ground is after the inverter?

Thanks.

**Jackso** · 07-12-2004, 03:18 PM

You should be able to use the 12V coming out of the power supply. However, to reduce noise, I would use the 12V from the power supply to activate a relay that provides the 12V (from the battery) to the amp. Or, you can use the ACC line from the car that is switched on only when the car is running. That would have the amps on whenever the car is running, but if you're like me, if the car is running, I'm listening to something.

Hope that helps.

**crosseye** · 07-12-2004, 03:24 PM

ACC is a good idea, but I want the capability to have the amps on when the car is off too.

I'll try running the 12V from the PS, if that doesn't work well, I'll try a relay.

Thanks,

[brian]

**Jackso** · 07-12-2004, 03:27 PM

The amps can still be on when the car is off through the ACC, it's usually power in the key back position, and the key forward position.

**crosseye** · 07-12-2004, 03:34 PM

Right, I dunno. I'll have to see what works best for my install.

Thanks for the info.

**lgbr** · 07-12-2004, 06:21 PM

I went to radio shack and got a Y-adapter for the computer's power supply, this way I don't cut factory wire. Spliced the yellow wire to the +12V remote lead, and it works fine.

**crosseye** · 07-13-2004, 03:18 PM

Originally Posted by lgbr

I went to radio shack and got a Y-adapter for the computer's power supply, this way I don't cut factory wire. Spliced the yellow wire to the +12V remote lead, and it works fine.

I've got plenty of those. Do you use an inverter, then a standard power supply? Or are you using a DC-DC solution?

My only concern is that the ground reference after the inverter will differ from the ground reference of the car (which the amps are grounded to). If they are different, the 12V signal (yellow wire) from the power supply could be either higher or lower than 12V with respect to the car's wiring.

I guess my other question was is it safe to create a common ground by tieing the power supply's ground to the automobile's ground.

How did you do this?