I am confused on how to wire the wiring harness for the head unit

[imbored408 10+ year member]

I plan on having 4 speakers connected to an amp. Amp connected to HU through RCA's.

The wiring harness has RCA's on them but I guess those are only for if I am not using an amp.

All I have to do is connect the

Power Antenna

12V Constant Power

12V Switched Power

Chassis Ground

(Amplifier Turn -On

Amplifier Ground)?

Do I just ignore the F/R speakers cables since I will be using RCA's from my amp?

If what I wrote is correct, what do I do with those RCA's on the wiring harness? Rip them off(not srs).

Click to read more...

 

[Bettr n' Revrse 5,000+ posts]

Just ignore the speaker wires...

 

[skylineTT 10+ year member]

tape and cap anything not used. cap all of the speaker wires from the head unit and wrap them up. make sure the RCAs that you arent using are covered. the RCAs from your head unit to the amp are the only thing you need for signal, then the speaker wire from the amp to the speakers.

 

[imbored408 10+ year member]

And I think they were supposed to send me this harness instead Metra 70-7550.

Anyways. So I just leave those wires dangling?

NVM it was answered

 

[keep_hope_alive Premium Member]

the harness you bought has RCA's to feed the factory amp from the aftermarket HU RCA outputs. pretty cool you got that, but you don't need those RCA cables. the problem is that you'll want to tape each one up.

i assume you have aftermarket speakers that are wired to your aftermarket amp? if you're using factory speakers and factory amp, then you plug the RCA male plugs from the harness into the HU outputs.

if you have an aftermarket amp and new wiring to each of the aftermarket speakers, then you simply run your long RCA cables and a remote turn-on from the HU to the amp.

 

[keep_hope_alive Premium Member]

we need more information, starting with make/model of the HU, amp, and speakers.

and i agree you need to cut off any exposed wire on the HU harness speaker wires and tape them up separately. you can also turn the internal amp (IC) off.

 

[imbored408 10+ year member]

i have a 95 240sx se

I am replacing all the speakers and headunit

I will have the speakers connected to the aftermarket amp and the amp connected to the HU with RCA's.

So on those pictures where do I connect the remote turn on wire to? The 12v Switched Power or the Amplifier Turn on? I would assume Amplifier Turn on but that harness doesnt even connect to the HU in any way so I am confused.

 

[Fiendstolemyamp 10+ year member]

You connect the blue wire coming from the head unit to the remote turn on terminal of your amplifier. The amplifier turn on & ground on the other wiring harness won't be used, they are for the factory amp, which you won't be using.

 

[imbored408 10+ year member]

ooo thank you. thought that was for the antenna but on the HU there is a separate plug thing for that.

 

[Fiendstolemyamp 10+ year member]

No prob.

 

[imbored408 10+ year member]

It also tells me to connect the Black Ground Wire from the harness to the Black Ground Wire from the HU.

I thought I was supposed to only ground the Black Ground Wire from the HU and leave the harness one alone.

What do?

 

[Fiendstolemyamp 10+ year member]

You can do it either way. If you want to just ground the HU yourself that's fine. If you ground it to the black wire on the harness you will be using the ground that was already there for the factory unit (prob easiest).

 

[imbored408 10+ year member]

aight thanks again

 

[Fiendstolemyamp 10+ year member]

NP bro

 

[keep_hope_alive Premium Member]

Not the blue wire!!! Blue/white wire on the head unit is amp turn on. Blue is for antenna, only on when radio is on.