If you are installing an aftermarket radio in your 2004 2005 or 2006 Acura TL this combination of harnesses are all you will need. This harness combo allows you to retain your factory amplifier, subwoofer and navigation. Your radio will need to have 5/6 RCA ports on the back label FL, FR, RR, RL,SUB if your radio does not have these outputs you will need a line out converter found here.
The 20 Pin Blue connector in this combo is used to provide:
– Steering Wheel Control + Lead
– Primary Speakers (FL, FR, RR, RL)
The 26 Pin Grey connector in this combo is used to:
– Amp Turn On for Factory AMP
– Retain Factory Subwoofer
– Retain Factory Navigation touch functions including buttons