Vacuum tubing

["vin2105 <phil@xxxx>" <phil@xxxx>]

Yesterday I took the binacle out to clean up the former owners idea of 
aftermarket stereo installation ( a taped bundle of wires almost as big around 
as my wrist) and found a small hard plastic vacuum tube running under the 
binacle that had been melted in half at some point when a wire had shorted 
and burnt. 
Could someone please tell me the function of this tube and what kind of 
vacuum related problem fixing this will clear up.

Thanks
Phil Priestley
vin 2105