Vt calais stereo crackling problems

[frymonkey]

I recently put a new mast and rope in my electric antenna motor, now the stereo when playing only plays at a lower volume and when you turn it up it crackles. also when you use other instruments it pops and crackles.... applying brakes-pops and gets louder, each level that you turn the fan higher it crackles and gets louder with each click of the fan and when you use headlights the sound also gets louder. This is happening with both radio and cd, all speakers...
Does anyone know what the problem could be? did i maybe short something out when i was playing around with the electric antenna?
Its got m stumped! any input would be very appreciated.