What was found
FWD CAB ZONE TEMP LIGHT CAME ON DURING RECALL OF MASTER CAUTION DURING LANDING CHECK. ALSO, COMES ON DURING RECALL ON THE GROUND. ACFT GROUNDED. REPEAT WRITE-UP, THE STBY PACK FAULT LIGHT CAME UP ON THIS AND 2 PREVIOUS WRITE UPS BUT SUBSEQUENT TESTS ARE GOOD IMMEDIATELY AFTERWARDS. NR 1 TEMP CONTROLLER WAS ALREADY CHANGED. STUDYING WIRING DIAGRAM 21-61-13, THE FWD ZONE BACK UP SENSOR IN THE CONTROLLER LEADS STRAIGHT TO THE FWD PASS. CABIN TEMP SENSOR. INSPECTED FWD PASS. CABIN TEMP SENSOR AND FWD CABIN TEMP BULB, BOTH WERE COVERED WITH DUST. CLEANED BOTH THE TEMP SENSOR AND THE TEMP BULB, GROUND FUNCTIONAL TEST GOOD IAW AMM 21-61-00-700-806-002, ALSO, RAN PACKS FOR 10 MINUTES WITH NO FAULTS AFTERWARDS.