XTRONS Car ISO Harness Adapter Connector Cable with High to Low Impedance Converter, Android Auto Car Stereo Radio Player compatible with Au-di A3 A4

How To Use 1. Turn OFF the unit, and locate the amps and the harness cables. 2. Remove the ISO harness from the XTRONS unit. （Support XTRONS IN79A3AP, IN79A4AP, IB79AA3RP, IB79AA4RP, IB79ATTRP, IB89ARAPL, IB89A4APL ect.） 3. Plug the red and white RCA connectors into color-coded jacks on the harness adapter. 4. Connect the harness adapter to the original harness of the XTRONS unit, it will perform as an extension harnessable here. Plug the harness back into the unit. Car ISO Harness Adapter Connector Cable with High to Low Impedance Converter Compatible with XTRONS head units or other unit (fit for Au-di A3/A4 models) which use 40 pin harness. It would solve your problem that the vehicle's rear speakers have no sound or have static noise after installing car stereos.