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I really need a quick answers to this

installed a new head unit, and i tested my car alarm (genuine oem) and now my car alarm is not as loud and it breaks up when it sounds like its not "tuned in"

can someone please tell me why its doing this?

cheer paul

did you test it before the install? sounds like a bizarre one if it's to do with the HU?

yeah i did pal, its still under warranty so if its still cocking up i will take it back to vw and let them sort it

its the after market head unit vw sell as well but i got it for roughly half the price

paul

yep, definitely take it back and see what they say, sorry can't be of more help

Do you know if your OBDII port / Diagnostics still work fine?

I've installed many stereos in VAG cars and there is a wire called K-line in the standard ISO connectors that you need to be careful of when connecting a aftermarket unit.

Basically this is a wire that allows you to make changes and stuff to your stereo using diagnostic software such as Vag-com. This is feature is lost when a aftermarket stereo is put in, so you need to make sure that no wire from the new headunit is actually connected to, as it is known to do some damage if there is - might be related to this somehow?!

thanks pal, well i have simply put my new head unit in, bought a cable adapter thing from halfords plugged it in and its working fine, only wires i have plugged in are the 2 ones that require the unit to have power

only thing that seems to be wrong with the car is my alarm, this k-wire is this connected to the old stereo?

Your old Gamma Tape / CD Deck will be connected to this K-line.

This wire won't be something you plug in like the power ones, its already on the harness so you need to make sure no wire on the aftermarket adaptor you bought connects to the pin on the harness.

Have a look at this:
http://www.ross-tech.com/vag-com/aftermarket-radio.html

It says which pin in the car's harness is the K-Line.