Aftermarket stereo and VCDS

Hello
Awesome club
Recently purchased 2000 Jetta TDI (ALH) with aftermarket radio
I've been a 1.6D lover for years but had to look into the TDI
I bought the KII-USB interface from Ross Tech(KermaTDI)
Program booted up fine on PC but I keep getting a "not plugged into car" reading
Checked the #12 fuse(7.5amp) it's fine
Unplugged the radio harness and still the same reading
The light on the interface has never come on (green or red)
Brand new interface so I have to believe it's this aftermarket radio dilemma
Unhooking the radio would be the same as clipping the k wire correct?
Any help would be great
Love these cars
Thank you
Mark

Have a look at the voltage between pins 4,16. You can try the parts store tester if the port looks OK.

I've been identifying the wiring using the Bentley's manual but haven't solved the problem yet. Tested voltage between 4 and 7 on DCL with key and radio on & read 10.3v so that is over 9v. If this indicates k line is at fault wouldn't unplugging stereo allow DCL to function properly with VCDS? So 4 to 16 would be ground to hot? We'll gonna follow some more wires and see if I can track this down. Thanks jcrews

sometimes the aftermarket radio connector will still cause the issue. You have to remove the connector as well.

Hello Richard
I figured as such and removed the new radio connecter when I unplugged the stereo. Didn't make a difference.PO of car said he had the stereo put in by a pro but the use of electrical tape for wire splicing doesn't seem to professional. Don't get me wrong I like electrical tape. From what I gathered from wiring diagrams the grey/white wire at radio harness is the k line is that correct? I've taken a couple pics but can seem to download them. I'll persist, this is a great machine

On the OBD connector, you need ground on pins 4 & 5, K Line is pin 7 and battery power on pin 16.

You should see a light on the Ross-Tech cable as soon as it is plugged in, even without the key on if pin 16 is live.

Did you see this from Ross tech's site?:

http://www.ross-tech.com/vag-com/aftermarket-radio.html

Maybe something to help...Mark

Hello guys
I did read the Ross Tech article it got me headed in the right direction.So a friend stopped by with a 2000 Subaru and I plugged interface into his car's DCL and no light came on. Turn his key still no light. Would this work as a test for the interface? I haven't been able to test a vehicle yet so I can't register with Ross Tech. I'm sure they can solve the problem if the interface is faulty. Just want to mention the car runs great still gets high 40's mpg with 230,000 miles. Thanks

Just wanted to finish this thread by saying that anyone who buys a tdi should buy your products through Kermatdi and Ross-Tech. Two of the best companies out there today.
Thank you