hey searched the forums and online but havent seen anyone with the same problem.
i have a 2006 fiat stilo and decided to replace the original stereo with a new sony mex-bt3000. now on the new iso connector i joined the yellow and red wire to power the unit as ive seen online. now i have power to the unit but no sound? not even static out of any speaker. now i put the old unit back in and it didnt work UNTIL i plugged in the small yellow single wire iso which originally plugged in over the black iso. there is no connection point for this yellow iso so just wondering is there a way to connect it up to the other iso to get it working? thanks

You have the Sub in the boot? If so you have the upgraded sound system where the speakers are externally amplified. All you need to do is attach the wire from the little yellow connector to the remote of the Head unit loom. This will tell the amp to turn on with the HU.

cheers for replying so quick volxstu. yea ive the sub in the boot. i know im going to sound like an idiot but what do you mean by the remote of the hu loom?