Go to the DIY section and open the thread called ACC 5th Gen... The site linked has a pdf of the 94 shop manual.

The brake light will come on if the fluid in the brake master cylinder is low (or the level switch is faulty) or the emergency brake is on (or switch is faulty).

When you unplugged the brake fluid cap, you took the switch out of the circuit. In order to be thorough, I would put a volt meter on the leads going to the engine and make sure the the resistance is infinity (open circuit). If that checks out ok, then the wiring to the brake cylinder is circuit is fine as well.

As for the emergency brake switch, you will have to remove the center console and unplug that switch. The instructions for the two swtches in the electrical system pdf (page 23-145). If the light goes off, then the switch is the problem. It may need to be cleaned or replaced. The switch is open when the brake is off. Do the same type of test on the e-brake swtich. To remove the console, remove bolts under the cup holder and the ones under the cover inside the compartment. The console will slide back and out.

 

In Hondas that brake warning lamp indicates either the handbrake is on, or the fluid is low.

But... As the brake pads wear out, the caliper pistons push further out, drawing fluid out of the reservoir. The size of the reservoir is such that the low-fluid switch often closes when your pads are worn down. That is, if you haven't been adding fluid occasionally.