'88 5ktqa brake warning light mystery

[Ben Swann]

Ever since I have put this '88 5ktq avant back together again and pretty much eliminated any quirks, a problem still eludes me.  Brake pads are relatively new all-around, all reserviors full and power steering pump has been changed to known good working one, fresh pentosin hydr. fluid, etc.  Yet I get this brake warning symbol when the ignition is turned on, regardless of whether engine is running or not.  This is the Brake or ((!)) symbol which stays on for the duration while ignition is on.  Occasionally I get a red triangle warning for brake pads worn when I step on the pedal hard/more forceful braking.  I checked the lead to the padwear indicator and both sides in front have continuity, and being sceptical, I bypassed them with a jumper wire, but it doesn't  help.

ABS seems to be working fine, and braking and steering seems to be working fine.

Anyone have this happen before?  What could be triggering this?  Perhaps there is a sensor somewhere that I have overlooked - so far I have checked: 1) pad wear indicator leads front right and left, 2) power steering /hydr. fluid reservior, 3) Brake fluid reservior 4) pressure sensor located at back of MC/brake booster  cyl.  There is another set of leads near brake res. tied off that are not connected to anything, but they were that way and I think I have seen them tied off on other cars. 

Ben