Where is the ABS main relay located on the 2002 Mercury Sable?

The same relay won't be doing the turn signals and the brake lights. The most obvious thing apart from bulbs is the brake light switch, which is easy to test with a multimeter.

https://www.google.com/search?q=2001+mercury+sable+brake+light+switch

and it is a known issue!

https://www.google.com/search?q=2001+mercury+sable+brake+light+switch+problems

....

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 ...

When on, this means the anti lock brake system is not functioning. The brakes will work however in a panic stop situation the ab a system will not function and the car will not stop as quickly. A code scanner that can read abs codes is needed to determine what the failure is.

should be either on floor to left of brake pedal or rt beside u before u get to shifter

abs valve power relay circuit failur,this is what the code c1266 meens,hope this was some help,all the best.

first you have to find what is causing the brakes to lock up as this can cause the ABS to activate turning on the light. once this is done then you can see if the ABS light is on, if so you will have to have the code pulled from the ABS module to know what to test.

check the over load circuit breaker for the lights going out. Run fault codes to find the ABS/ Traction control sensor problem

With the vehicle off, turn the key to the on position and see if there is an ABS light (usually yellow/amber). If so, the brake light is related to the emergency brake and the rear calipers aren't done correctly. If no ABS light, the brake light is most likely the indicator for the ABS system. a sensor is most likely unplugged, damaged or just knocked out of calibration with the ABS drum.

Hello Amanda.

There are two separate fuse panels.

One is under the hood under a flip up black cover near the battery. This one is called the battery junction box.

The fuse panel inside the car is located below and to the left of the steering wheel by the brake pedal. You will need to remove the panel cover below the steering column to access the fuses. This one is called the central junction box.

If you need further help in locating the panels, ask me here in a comment.
Thank you for using FixYa.

KL

ABS light on problems are either the result of bad wheel sensors, bad connectors, or bad ABS relay.

The relay is usually mounted to the top of the ABS module (it was on my '01 Tahoe). And until mine went out, I didn't know these things were problematic. I found a place in Moscow, IA that rebuilds them for $150 and gives a 5 year warranty. You pull your off, send it to them, and have it back in less that a week.

Find their website by Googling ABS repair, Moscow, IA. They have a troubleshooting guide and everything on their website.