MR2 Roadster Owners Club

The Workshop => Audio / Security / Electrical => Topic started by: Anonymous on April 21, 2006, 20:28

Title: Headunit Wiring
Post by: Anonymous on April 21, 2006, 20:28
Im just about to fit my new shiny Alpine headunit tommorow morning so i opened up the box to take a look at all the bits and how the wiring bit will work.  

I noticed that the wiring bit that you connect into the back of the headunit and into the autoleads iso converter cabling has the yellow and red cables unplugged.  I have read that one is the ignition and one is the constant power although im a little unsure which way to connect them as i remember in my old car i had to switch the cable around so yellow went to red and red went to yellow.  Does anyone know the correct way to wire this bit?.

If i plug them in wrong and plug the stereo in, could i blow up my car?.  I understand this is probabaly an incredibly stupid question although im just concerned about messing it all up.

I also read in the alpine manual that you are meant to disconnect your battery (the black cable) when you install the stereo.  Is this really necessary?.

Any help appreciated.
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Post by: red_leicester on April 21, 2006, 21:02
The red and yellow depend on the head unit.  Best idea is to try it with yellow to yellow and red to red, then if its wrong switch them round.  Will not do any harm, it just determines whether the radio remembers your presets etc when you turn the ignition off.  Try it and see.

I don't think you need to disconnect the battery.  I didnt and I'm still here to tell the tale   s:) :) s:)
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Post by: GSB on April 21, 2006, 21:49
As always, RTFM before doing anything...

Alpine disconnect these wires on purpose, as they prefer to have a dedicated power supply run direct from the battery, rather than use the cars own supply which may not be man enough for the job.
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Post by: Anonymous on April 22, 2006, 10:54
I put in a new head unit last week. Rather than disconnect the battery i just removed the 2 radio fuses whilst i was mucking about with the wiring harness.