Car audio which wires go from head unit to amp in a car

Lights? No?
Check power cables.

Any sound at all (click, hum)? yes?
Check audio cables.

Any sound at all (click, hum)? No?
Check speaker cables.
Check speakers.

Is head unit sending audio?
Try connecting direct to speakers. Working? Amp has fault.
Not working? Head unit has fault or is wrongly wired to amp.

First disconnect the CD head unit from the sub amp and see if the other amp works. If yes, the problem is the wires to the amp, the amp itself, or the subs/sub wiring. If no, the problem is the head unit--probably an internal short.
If the other amp works with the sub amp disconnected, reconnect the sub amp to the head unit, but disconnect the sub wires from the amp. Try the CD player. If the amp goes to protect with no speaker wires attached, the amp is bad. If the amp is OK, the problem is the subs or sub wires. Hook the wires up to the amp again, but disconnect them from the speakers. Try the player again. If the amp goes to protect, the problem is the amp wiring. If not, the problem is the subs. Check the impedance of each sub using an ohmmeter to determine which amp is out of spec.
Please let me know if you have questions, and thanks for using Fixya.

The head unit must have remote-on capability. If there is no hole in the head unit than you must use some other form of power on. If the Amp supports it, use the audio on setting (look in the manual for this). This turns on the amp once it receives audio signal from the head unit.

The only wire that you should hook up from the amp to your head unit is the remote power wire which is the blue wire on the wiring harness for the head unit. Sometimes they are blue with a white stripe. Hope this helps.

The remote wire is supposed to be connected to the remote output on the back of the head unit that is feeding the amp.
Without the remote wire hook up the amp will not turn on.
Reason for this is, the Head Unit tells the AMP to turn on, without the remote connected the AMP is going to do nothing, find the remote switch wire on the back of your Head Unit and run the wire to the remote input on the AMP.

Power amps must be connected + battery wire to the amp +b terminal with a gauge 8 or bigger depending on the power rating, - ground to the car chassis as short as possible,connect cords from head unit to power amp with good groundings, and remember to connect the speakers and the remote trigger from head unit to turn the amp on.

Yes, and would imply that the amp is powered up all the time.

You should correctly wire your system by

1.Connecting the constant 12vdc input wire to a constant 12vdc source to power the in-dash head units memory.

2.Connecting the switched 12vdc input wire to a switched 12vdc source to power the head units primary functions.

3.Connecting the remote output wire (typically a blue wire) from the in-dash head unit to the correct terminal on the amp, so the amp will only power up when the head unit is on.

4 Remember to run the signal (speaker) wires in a chase separated from the amps power wires, so as to avoid a buzzing noise in the speakers.

5. Always use an in-line fuse on the amp and the head units main power wires.

Note: A properly powered amp will produce a better sound quality then if it were under powered, so be sure to use the proper wire gauge as your amps power supply.

Good luck
Aduz

your amps rem wire is hooked to the power antenna wire on your head unit and so when you turn off the radio you would nolonger need an antenna so it powers down and would lower the antenna.Depending on the head unit you should have one output for the power antenna and one for the amp rem......If your head unit doesn't have the rem output you can wire it to the switched wire that powers your head unit but keep in mind the amp will stay on while you have the key in acc or run position even if your head unit is off.
hope this helps!

Hi,

The basic would be to wire the sub amp to your batteries with the trigger/remote wire powered by your car stereo/head unit. When your head unit is turned on it will in turn power up the sub amp. Of course the sub woofer need to be wired to the amp. For the signal/audio wiring, normally, the head unit has a stereo RCA female connectors at the rear intended to be connected to external amps through a pair of shielded/audio cable terminated both ends with RCA males. Some units have a special RCA specifically for subs. Most eternal amps also uses RCA for their inputs.

If the existing car audio system has already an external amp and your plan is to add on to this, the audio/signal from the head unit could be split to provide both for the existing and the new sub amp.

If the existing car audio does not have an external amp and their are no RCA connectors at the rear of the head unit, it is still possible to connect an external/add on amp by using an adapter that connects to the speaker wires of the head unit and converting it out to line level (through RCAs) appropriate for the input of the amp.

Hope this be of help/idea. Pls post back how things turned up or should you need additional information. it would also be nice if you can post brand/model of your head unit and intended sub amp.

Good luck and kind regards.

The remote wire from the amp is connected to a blue wire behind your head unit. This is a power antenna activation wire; it's only active when the tuner is selected. Switch the remote wire to a blue/white wire at the head unit.