My blower motor dosent work on my 2005 mercury sable

Question edited for clarity.
Question moved to model category.

Relay 4 in the engine compartment fuse box.

Mercury Sable (2000-2005) fuses and relays

https://fuse-box.info > mercury > mercury-sable-2000-...
2000, 2001, 2002, 2003 - The fuse box is located below and to the left of the steering wheel by the brake pedal. The location of the fuses in the passenger ...

Check HTR - AC fuse and HVAC fuse.check blower motor. it could be faulty.

Free wiring diagrams here http://www.bbbind.com/free-tsb Enter vehicle info. Year , make , model an engine size. Under system click on HVAC ,then under subsystem HVAC controls . Click the search button then the first blue link. Scroll down to the # 3 diagram . Shows fuse's , relay ,blower motor an the resistor . Does the blower work at any speed ?
Blower Motor Problems Auto Repair Help

Your owners manual should have this info. If you don't have an owners manual, you can go to,
fleet.ford.com
Scroll down the page, click on owners manual, It'll ask year--make--model. I believe the fuses start on page 125.

Here's a link to your fuses Jack. Mercury Sable Fourth Generation 2000 2005 fuse box diagram Auto Genius

Suggest you check fuses and relays in the fuse boxes first.

Use your browser and search for "2001 Mercury Sable Blower Wiring Diagrams"

Check this website:

https://www.autogenius.info/mercury-sable-fourth-generation-2000-2005-fuse-box-diagram/

in your owner manual and usually in fuse panel. You have a fuse panel in car and under hood.

in car

if you have an owners manual there should be one in there but if not it should be under the cover to the fuse box also there is one under the hood of the car as well