1999 mercury grand marquis 4.6 serpentine belt routing?

Answer 1

The 1999 Mercury Grand Marquis has (2) TWO engine styles, both different. The style for Vin numbers with a "W" engine, and the Vin numbers with an "X".

The "W" series has the A/C Compressor to the RIGHT of the engine when viewed from the front.

The belt circles all components from the outside but two (2). The idler wheel located on top to the right of the alternator, and the tensioner pulley, located to the right and between the Crank and Water pump pulleys.

The belt goes UNDER the idler pulley, and passes to the Tensioner pulley BETWEEN the crank pulley and the water pump pulley.

As for the "X" series... The Belt goes, in clockwise rotation, from the outside looking AT the engine:

Starting with the top most component, OUTSIDE the Alternator, OUTSIDE the steering pump, INSIDE the water pump (V grooves on belt showing),OUTSIDE the crankshaft pulley, INSIDE the tensioner (V grooves on belt showing, again),OUTSIDE the A/C Compressor, and then towards the Alternator again. The Idler wheel presses against the belt on this return leg from the smooth side.