The brake warning light comes con as a result of the monitoring system
seeing a higher than normal resistance from a bulb. You could have a
corroded set of contacts in the bulb holder or the tail light housing as a
result of water getting in. It is also passible that the monitoring "box"
is bad or that there's a wiring problem (high resistance path in the
wiring or ground return).

I'd suggest that you pull each of the bulb holders and check them for
evidence of corrosion. You should also inspect the tail light housing for
evidence of corrosion. If that looks okay it's time to check the wires and
grounf return for high resistance.

I didn't see your first post - what model?  If an E30 try a new brake light
switch.

Sorry, it's a 325es

I'll check connections and, if necessary, a break light sw.

Thanks,

Don

CHECK BRAKE LIGHT CIRCUIT is not telling you that a brake light is not
working, that warning is more specific to the actual brake light that is out
of service.

Check Brake Light Circuit originates on the switch itself that is mounted on
the brake pedal. There are two of these swtiches, I am not sure which one is
giving you fits.

Don,
You may have to replace the brake light switch.  Pretty easy to do
yourself.  It fixed the same problem on my "94 325i