Thread: Advice re Red and Yellow Power for modern Car Audio

Hi Folks,

I have an Alpine head unit that has the standard switched +12 Red and permanent +12 (Yellow) to the Battery which is as a general rule standard for operation.

The question is does the Yellow provide the main current draw when on as the wiring harness has yellow as the heavy gauge wire. So do I have this right that the yellow supplies memory and all power once it receives the switched voltage from ignition?

Or is yellow, although heavy gauge is memory only.

Any advice on which wire provides the main flow of current to drive the amp will be appreciated, regards Geoff

Originally Posted by mousie

Hi Folks,

I have an Alpine head unit that has the standard switched +12 Red and permanent +12 (Yellow) to the Battery which is as a general rule standard for operation.

The question is does the Yellow provide the main current draw when on as the wiring harness has yellow as the heavy gauge wire. So do I have this right that the yellow supplies memory and all power once it receives the switched voltage from ignition?

Or is yellow, although heavy gauge is memory only.

Any advice on which wire provides the main flow of current to drive the amp will be appreciated, regards Geoff

that's a good question, from what I have seen the main current draw is via the 'yellow' or constant power connection, if you pull your head unit apart and take a look (at least in most that i have dismantled) the 'yellow' wire goes tot eh main 'supply' rail of the headunit, though I have seen some (a clarion unit) that worked opposite to this, when I have wired in units without ISO harness (no longer into high power car audio so these suit me fine now despite the power loss and lower audio quality you get) I have always beefed up both wires and fused both links, power the 'red' or ignition supply via a relay to lower the overall current pulled from the 'ignition circuit' this way it doesn't really matter which is pulling more current.

you could measure the current draw from each if you wanted to for a definitive answer.

Leroy