Radio Harness Has no 12V Power

[MikeyF 10+ year member]

So, my stock radio harness does not have a 12V wire. The Eclipse and after market harness do, but the stock does not. Was wondering how exactly I go about hooking the head unit up, and where I would direct the 12v wire.... Car is a 2005 Monte Carlo. Any help would be greatly appreciated. Thanks.

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[benzmansl65amg 10+ year member]

run from battery or fuse box

 

[*SlappinAzz*]

tap into the fusebox

 

[MikeyF 10+ year member]

Already tried to hook it onto one side of the fuse for the radio. Radio did not produce any sound, and did not turn off when car turned off. Had to manually hit power on the radio, after the car was turned off.....

 

[SilveyPuck08v2]

Go to AutoZone & buy a BussLink "add a fuse module" then tap it into any 12v constant sourcein the fuse box. Other option would be wire it directly to the battery (& fuse it at the battery).

 

[matt_bennett05 10+ year member]

Yeah make sure that the red wire is hooked to a ignition switched 12v source but the yellow wire has to be on a constant 12v so you retain memory 24-7.

And just a head's up it would be a great idea to run a ground rather than tap into the factory ground ! ! ! i.e. bigger wire than stock to better ground spot

 

[SilveyPuck08v2]

Yeah make sure that the red wire is hooked to a ignition switched 12v source but the yellow wire has to be on a constant 12v so you retain memory 24-7.
And just a head's up it would be a great idea to run a ground rather than tap into the factory ground ! ! ! i.e. bigger wire than stock to better ground spot

this ^^^^^

my gf's '00 Grand Cherokee had an isolated 10g ground factory, which was nice.

 

[xoutofmyheadx 10+ year member]

then how does the radio even turn on?

 

[MikeyF 10+ year member]

Yeah make sure that the red wire is hooked to a ignition switched 12v source but the yellow wire has to be on a constant 12v so you retain memory 24-7.
And just a head's up it would be a great idea to run a ground rather than tap into the factory ground ! ! ! i.e. bigger wire than stock to better ground spot

What do you mean by ignition switched 12v source? Yea, the yellow wire (memory wire, correct?) from the radio and the harness would just be wired together, correct?

 

[Phoenix Risen 10+ year member]

the red wire is your ignition switched 12v source, or simply put the acc. wire.

 

[MikeyF 10+ year member]

Yeah make sure that the red wire is hooked to a ignition switched 12v source but the yellow wire has to be on a constant 12v so you retain memory 24-7.
And just a head's up it would be a great idea to run a ground rather than tap into the factory ground ! ! ! i.e. bigger wire than stock to better ground spot

I understand what the acc wire is.... My question more so is what is a ignition switched 12v source, or where would I find it? Like I said, I tried to tap into the radio fuse, and the radio stayed on, with no output from the radio or amp....

 

[daboyfrumdabx 10+ year member]

I understand what the acc wire is.... My question more so is what is a ignition switched 12v source, or where would I find it? Like I said, I tried to tap into the radio fuse, and the radio stayed on, with no output from the radio or amp....

Radio fuse is a constant source. Tap into your wiper fuse and you'll be fine as the wipers only work when the key is in the "ACC" or "ON" position and turn off with the key.

 

[xoutofmyheadx 10+ year member]

Comment by ModifiedLife on March 31st, 2009 at 2:50 am

Kamona, use the orange wire in the ignition switch harness located inside the steering column. Hope this helps. Good luck.

found this on another site.

 

[Wingman0121 10+ year member]

If there isn't a 12v constant power wire then how did your stock radio work before? Every car has a 12v constant power wire somewhere in the stock wire harness unless it didn't come with a radio from the factory.

 

[bubbagumper6 5,000+ posts]

OP: By ignition switched wire they mean a wire that only has power when the car is on. This is the wire that allows your radio to turn off when you turn the car off. You need another wire that has a constant 12V regardless of the car's condition (on or off) so when the car IS off, the radio doesn't lose all power and reset to factory default. If you can't find one or both of these in your dash you can tap into fuses to get the right signals. As stated before you can use the wiper fuse, or anything else that is only powered when the car is on. If your not sure, grab a digital multimeter ($5 at walmart) and check which fuses are live all the time and which are only live when the car is on.

Comment by ModifiedLife on March 31st, 2009 at 2:50 am Kamona, use the orange wire in the ignition switch harness located inside the steering column. Hope this helps. Good luck.

found this on another site.

Why would he need to dig into the steering column? That's just adding extra work.