This is a weird one for me, so i have a car Gps which works fine for me but the cigarette lighter plug was rubbing on the gas tank,so i bought a hard wire cable and simply tapped into the cigarette lighter wires which in turn caused the radio to lose almost all reception so i then tapped into the accessory plugs above the headlight and all reception came back, can someone please explain to me why this happened??

 

Did your power wire, when tapped into the cigarette lighter run along or near the coax antenna wire? Eddy current from the power wire can do that.
Other than that, the only other thing that comes to mind is your flux capacitor is interrupting the radio signals' sine wave and changing the space-time continuum.