I've got a '95 Civic LX 4 door, having a strange problem with the dash brake warning light coming on. Brake are NON-ABS. Started doing this recently as we began having cooler temps, around 55-60F in the morning. Light would be on when I first started driving, and would go out after about 5 mins or so of driving. Tonight it was a bit cooler around 50F. Light went out after a short drive, but if I pressed the brake hard the light would come on for a few seconds, then go out. Pedal is firm, does not sink to the floor, braking performance is fine, doesn't pull, handbrake is good, I can skid the back wheels with it OK. Checked the MC fluid level, full with no loss of fluid, no leaks.

Most recent brake job was about 6 months ago. Replaced front pads with Axxis Ultimate from StreetBeat Customs $57 incl shipping. These pads do create a lot of dust, but they are much better than the metal masters I replaced (they don't stop well when pads are cold). Flushed and bled lines with fresh Honda fluid. Also put new NAPA shoes on in the back, adjusted for a good pull on the h-brake, drums and wheel cylinders were fine.

Could I just have a brake warning sender unit going bad? Where is that thing in the brake hydraulic system anyway? Only wires I can see on the MC is the float level sense hookup, but the fluid is full, so the float should read no warning signal. What else should I be looking at? This problem never happens in warm weather, in summer over 60F.