What was found
(CAN) DURING FLTS WHEN DE-ICE SYS IS DEPLOYED & OAT IS IN -30 & BELOW RANGE, & EITHER 1 OR 3 MIN CYCLE DURATION IS SELECTED, SYS INDICATES PROPER OP THROUGHOUT CYCLE. UPON COMPLETION OF CYCLE AMBER DE-ICE CAWS CAUTION WOULD ILLUMINATE IN CONJUNCTION WITH FLASHING GREEN DEICE CAWS, THUS INDICATING FAILURE: WHEN SYS IS TURNED OFF & THEN BACK ON ENTIRE PROCESS WOULD REPEAT.THIS PROBLEM DOESNT APPEAR TO ARISE WHEN OP AT WARMER TEMPS.WHEN TROUBLESHOOTING TO IDENTIFY FAILED PART OF SYS IT DETERMINED (ON SEPARATE OCCASIONS) THAT OUTBOARD UPPER & OUTBOARD LOWER L/H & R/H PRESSURE SWITCHES WOULD APPEAR TO BE STUCK OPEN INDICATING FAILURE THAT SIMULATED INFLIG HT SYMPTOMS. BY REMOVING SWITCHES & APPLYI