how do i find the serpentine beit routing diagram for a 1999 volkswagan passat 1.8 t turbo

if its not located somewhere under the hood, or in the owners manual, may have to cousult the local parts house - they usually will give free advise in these situations.

1 - Pulley - generator 2 - Pulley - viscous coolant tan 3 - Pulley - power steering pump 4 - V-belt - power steering vane pump and coolant pump. See table column A below. 5 - Ribbed belt - generator, viscous fan, power steering pump, crankshaft and tensioning roller. See table column B below. 6 - Pulley - coolant pump 7 - Pulley - crankshaft 8 - Tensioning roller 9 - Pulley - A/C compressor 10 - Fibbed belt-crankshaft, tensioning roller and A/C compressor. See table column C below. 11 - Tensioning roller

I hope That helps