Need serpentine belt diagram 4 merc sable 3.0

You don't say which 3.0 V6 u have, there are two, OHV and DOHC so will give u both diagrams, go to the web link (PDF file) and scroll to page 86 figure 5-7, the next one is page 87 and figure 7-12, just look at your pulleys to pick the right diagram.

...are under hood, a diagram on top of radiator support.

2004 MERCURY SABLE - V6 3.0L 182ci GAS FI N S
Multiple Accessory, w/A.C.



2004 MERCURY SABLE - V6 3.0L 182ci GAS FI N U and
2004 MERCURY SABLE - V6 3.0L 182ci FLEX FI N 2
Multiple Accessory

From DAYCO Catalogue

Hope helped (remember rated this) Good luck.