99 mercury sable power windows dont work, fuse is ok and interior light does not work

You didn't say if it would start. If it will not start, it is a dead battery.

check the fuses in the fuse panel. make sure the interior light isn`t burnt out and needs replacing. also some light switches(for the headlight) have a switch built within it that if its turned too far one way it will shut of the interior light function. if this not the problem then check for power and ground at the interior light socket as there could be damaged wire. if the fuses are good and the power windows don`t work then you will have to check the window switch for power and grounds as the other windows are feed through the drivers switch. if you have power and grounds then you may need to replace the switch. if you have no power or grounds then you will have to check for a broken wire were the wires go from the door to the body of the car as they have a problem with breaking. there is also a power window relay in the relay box.

I'm showing a brown wire coming out of the headlight switch on 96-99 models going to the park lights.
Do you have power on that circuit leaving the headlight switch ?

Check your fuses on your inside box cause one is probably bad

i would check the main fuse that runs the fuses box

The fuse panel that you want is located near your brake pedal. To find your fuse/relay location go to www.flmowner.com , type in the year make and model of your vehicle. Click on find my vehicle. Click on owner guide 1st printing. The information you are looking for is on pages 121-122. I hope this helps.

there should be a fuse under the dash for the interior lights. and the windows should have a relay under the hood in the distrubution box next to the battery.

The power windows don't have a fuse, they are controlled by a part called a GEM, this stands for Generic electronic module, if the wipers work ok then the power windows have power available, the problem is if the GEM fails the power windows become inoperable, what is the exact nature of the problem you have, I am a Ford rained tech so know the system very well.

If you have checked Power/Ground, and alls good look toward the Multi-Function Sw. (turn sig.sw) this is where everything get distributed at...as for your power loss when shifting, is it column/floor shifter ???? need to know....

There are 3 general location to most cars for the fuse box. The left side of dash behind a cover, underneath the dash just to the left of the steering wheel, or behind the glove box. It sounds to me that more than likely it's your fuses that went out.