I have the same issue with mine. I know there is a wiring harness you can buy$$$ for this purpose. I'll try to fine a link for you on FF.com. It is only for certain HU but I think there is one for Clarion.
Here you go:
http://www.pac-audio.com/products/swi.htm
Hope this helps.
Here you go:
http://www.pac-audio.com/products/swi.htm
Hope this helps.
2003 CD Silver SVT Focus
#21 of 2173
#21 of 2173