Stereo Wire Harness GMC Sierra 88 89 90 91 (car radio wiring installation parts) Aftermarket Radio / Stereo Installation Wire Harness Connection of Wire is Plug N Play - Plugs directly into vehicle harness (no cutting or splicing) Professional wiring harness (EIA color coded to match the aftermarket wiring) IF YOU CURRENT CAR RADIO STAYS ON AFTER THE KEY IS REMOVED (BEFORE DOOR IS OPENED) THIS HARNESS WILL NOT WORK PROPERLY