Brake sensor? something else?

First you need to have EBCM - electronic brake control module check for DTC'S - diagnostic trouble code's . If the light is on there is a code stored . I think most part stores can do this and for free . After you find out what code is stored , looking up that code in service repair information for diagnostic trouble shooting chart would be next step . There are a few codes too.
DTC C0035 or C0040
DTC C0045 or C0050
DTC C0110
DTC C0131
DTC C0161
DTC C0186
DTC C0196
DTC C0201
DTC C0240
DTC C0241 or P0856
DTC C0244 or P1689
DTC C0245
DTC C0283
DTC C0287
DTC C0290 or C0292
DTC C0455
DTC C0550
DTC C0558

Find the code do the diagnostic's , fix the problem , wiring issue's , a sensor , bad module ,what ever it is . The light will go out then . Here is a sample of code discription .
• DTC C0035 Left Front Wheel Speed Sensor Circuit
• DTC C0040 Right Front Wheel Speed Sensor Circuit

Traction control and anti-locks(ABS) lights come on there is sensors that are pluged in behind the rotors check and see if they are disconected or loose sometimes when you change your brake pads they might come loose and not making contact.

If brake pedal is chattering or pulsating it is most likely because you need either front or rear rotors, or both. They are rusted or out of round. If there is something wrong with either your abs or traction control,the abs or traction control light will come on & stay on. As soon as these lights come on, it automatically disables abs or traction control. If you would like to take out fuse that disables abs or traction control circuits, it will leave the lights on.You just wont have their functions. If by some strange condition your chattering goes away, then there is indeed something wrong with your abs or traction control.Fuses are labeled abs or traction either under hood or in your fuse panel in car.

chek the brake fliud level. if low light will set light and abs wont work.

well the cruise light is blinking probably becuase its telling you its notworking due to the fact the abs/traction lights are on,youre saying you just got a brake job done, i would guess either they unplugged the abs sensor to gain acess to the brakes or the sensor for the abs got dirty when they disrupted the brakes by removeing them to do the brake job, first thing i would do is peek at each wheel and see if the abs sensors are plugged in, if they are the next thing i would do , is remove each of the front sensors and clean them with brake clean or something like that,,the sensors are little magnets and sometimes when working in that area rust and dust and stuff gets on them and interupts the signal and casues all the problems you have list,,,,hope that helps,,,or take it back to where you got the brakes done and tell them about it and they should look at it and maybe fix it for free ,,,

Because the brakes were changed, either one of the sensors were broken when removing brakes or it has set a code. Go to your local autoparts store and have them reset the code. See if it comes back on. If it does you will need to look at the ABS sensors on each wheel and replace if damaged

it might be a loose abs cable behind one of the brakes?

ABS and traction control really are only for panic stops and if your tires slip on wet surface's and yes each tire has a sensor on it. However if the brake light comes on this has nothing to do with the ABS or traction control lights. It's not a parking brake light. This light tells you, you have a serious brake problem.

Sounds like you have a problem in the front brakes or a front wheel speed sensor. A common cause for a Traction light is a faulty front ABS wheel speed sensor or harness. When the Anti lock brake computer sees a problem in the ABS syetm, it disables traction control as well.

Prior to the brakes being replaced you more than likely had metal to metal contact which can throw metal shavings on the ABS wheel sensors. This metal shavings stick to the road grime on the wheel sensors showing the ABS computer a false reading making the ABS light come on. On Ford Windstars, the ABS light and the traction control light are on the same circuit. A simple (and cheap) fix is to pull the ABS wheel sensors and clean them with brake cleaner or throttle body cleaner. Make sure you dry them well and reinstall. On the Windstar there is one bold holding the sensors to the back of the wheels. I recommend you spray some WD40 on the bold and wait about 10 minutes before removing.
If this doesn't fix the ABS light and brakes, you can have the ABS system diagnosed at a shop for about an hour labor. (Usally about $100)
I have fixed many of these type of problems just by cleaning the ABS wheel sensors. Good luck.