Ignition noise suppressor for the radio, shouldn't hurt anything is it's disconnected. Actually not needed if you've upgraded your radio as newer radios have ignition noise suppressors built in to them.
3G Alt. Upgrade, Duel Batteries, 351M bored .030 over with Edlebrock cam and intake, C-6 w/AO4D internals, 3" lift w/RS 9000, 33x12.50 MTR's, Saginaw PS Pump Conversion, On Board Air, Detroit Locker, Hydro Boost Brake System, Altimeter from a CH-46D, Map Light from a MH-53E.
U. S. Government - Wasting paper and keeping Lumber Jacks gainfully employed since 1776.