1991 Honda Civic Hatchback, the brake lights are on all the…

1991 Honda Civic Hatchback, the brake lights are on all the time when the engine is running. I have replaced the brake switch, the ECU, and the ignition switch. I am at the point of changing the Integrated Control Unit under the dash, but I cannot find the part anywhere. It is very difficult to T/S the issue when there are two units at play. One is the ICU, as described above, and now the automatic seat belt unit is also in play. I have owned this SI since new, and have 295,000 miles on it, and have all the manuals. This unit might be called a Multi Function unit also. It is located under the dash on the left side.

Mechanic's Assistant: Have you checked the brake fluid? How's the level and when was it last changed?

The brake fluid is great, but if it means anything, I could take the top off and verify the level by turning the cap upside down.I just replaced all of the brake system, from the Master cylinder to the rear brakes, including new hoses. I am an A&P Mechanic, so these things are what I do...

Mechanic's Assistant: Are you fixing your Civic yourself? What have you tried so far?

Brake switch, Ignition switch, ECU, checked wiring...

Mechanic's Assistant: Anything else you want the mechanic to know before I connect you?

Like I said, I need an expert to tell me what to do next.