Try replacing the bulb first.
Couple of things. Check the ground for the loom at the rear. If that is clean and tight I would suspect that the problem is in the brake light switch.
Check the fuses then check the brake light switch.
Have someone stand behind the van while you press the brake pedal. It works equally well if you switch roles and have the other person do the brake pedal ;)
If your brake fluid is also running low, you probably have a help in your cruise control brake pressure sensor. The brake fluid shorts out the sensor and eventually you'll blow the fuse for the abs, AC, and spedometer/odemeter. Replace the brake pressure sensor. Its under the master cylinder resevour. Remove the air filter first and there lots of room to work. This is a relatively easy fix, the part is about $35.
My rear window brake light works, but not my tail light brakes on my 1997 Monte Carlo. What is the problem?
Press one click on the emergency brake. This works on most GM's.
Start with checking the bulbs, then the fuses. In most vehicles the brake lights and siganal lights and running lights are separate circuits. If the fuses and bulbs check okay check the wiring feeding the rear of vehicle.
I had the same problem, all I did was replace the fitting that the bulb goes in with a new one ( $8.00 fix) and replaced the tail light and haven't had a problem since.
Lift up on the E-brake until the first click. This works for any vehicle (Chevy at least) with daytime running lights.
The right brake light does not work on 1999 Ford Windstar. Tail lights and blinking light works. Changed bulb more than once, changed the plug in where the bulb goes but it still does not work. The tag lights are not working either.
One that works with OBD II.
I change the { E} brake switch where you pull it on that help me when my running light did not come on may that it works the same good luck