# MKIV Jetta Aftermarket Radio, Amp, Sub Install



## Robbie.Harrell (Nov 30, 2007)

Alright, I am new to all this stuff and have done my searching. I am looking to install a after market radio into my 2003 jetta Glx, It has the double dim monsoon system in it. I talked to the guy at best buy and heres what he told me. He said that because of the way that the radio is controlled to install an after market radio you have to wire it to the ignition. Is this true? I have searched and couldn't find any DIY's. If you have any information that would be great. Best buy wanted 50.00 dollars for labor to run the cord to the ignition.
Thanks
-Robbie


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## NesQuik (Nov 21, 2005)

*Re: MKIV Jetta Aftermarket Radio, Amp, Sub Install (Robbie.Harrell)*

You aren't very convincing when you say you have done your research. There is a yellow wire terminal marked x75 under the steering column that will do the job. You will run the red accessory wire to this terminal. I suggest adding a fuse a few inches into the line.
Read my buddy Pat's post for more information.
Firewall
Head unit install
Wiring
http://forums.vwvortex.com/zerothread?id=3565705











_Modified by NesQuik at 1:44 PM 2-7-2008_


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## NesQuik (Nov 21, 2005)

*Re: MKIV Jetta Aftermarket Radio, Amp, Sub Install (Robbie.Harrell)*


_Quote, originally posted by *Robbie.Harrell* »_Alright, I am new to all this stuff and have done my searching. I am looking to install a after market radio into my 2003 jetta Glx, It has the double dim monsoon system in it. I talked to the guy at best buy and heres what he told me. He said that because of the way that the radio is controlled to install an after market radio you have to wire it to the ignition. Is this true? I have searched and couldn't find any DIY's. If you have any information that would be great. Best buy wanted 50.00 dollars for labor to run the cord to the ignition.
Thanks
-Robbie

True. The red wire is not available on the harness.
The reason you need to do this is because if you have noticed the monsoon is able to be powered on/off even if the car is not turned on or in accessory mode.
The x75 panel makes sure the unit turns on with accessory mode. Adding a fuse in this line prevents a voltage spike from damaging the unit. The spike will stop in the wire.


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## kwalton (Sep 3, 2001)

*Re: MKIV Jetta Aftermarket Radio, Amp, Sub Install (NesQuik)*


_Quote, originally posted by *NesQuik* »_Read my buddy Pat's post for more information.

that's actually my picture you're using buddy.


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## Robbie.Harrell (Nov 30, 2007)

*Re: MKIV Jetta Aftermarket Radio, Amp, Sub Install (kwalton)*

Thanks Guys, Got it installed and it works great, vwvortex has always been great.


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## NesQuik (Nov 21, 2005)

*Re: MKIV Jetta Aftermarket Radio, Amp, Sub Install (kwalton)*


_Quote, originally posted by *kwalton* »_
that's actually my picture you're using buddy.























heh, sorry walt, link was on pats.


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## jdub_thc (Jun 19, 2010)

i installed an aftemarket headunit in my car but haven't wires up the accesory wire, for the time being I have to manually turn the unit on/off. Im installing a sub shortly so I fiqured i'd go and redo the wiring after, I have nothing but time, the only thing im confused about is which wire to run to the x75. The headunit red wire is connected the the red wire from the harness. What I have pictured in my head is this


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## MYK (Nov 24, 1999)

ya, red is ignition switched power and yellow is constant power.


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## Pat @ Pitt Soundworks (Nov 14, 2008)

No, don't do that.

You only need to run the head unit red wire to the 75x. Don't connect the factory harness to it.


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## MYK (Nov 24, 1999)

ha i didnt even really look at the picture. yeah you dont need to run it back to the harness. just from the radio to that terminal, dont forget the fuse please


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## jdub_thc (Jun 19, 2010)

i hada feeling it was done wrong, didnt seem like it made sense. appreciate the help


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## GTITDub (May 20, 2005)

what amp of fuse to use?


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## xhopesfall24 (Jul 2, 2009)

GTITDub said:


> what amp of fuse to use?


 Factory radio fuse is 25.


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## GTITDub (May 20, 2005)

xhopesfall24 said:


> Factory radio fuse is 25.


Ok, Thank you!


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