What was found
(CAN) SMOKE AT NOSE OF AIRCRAFT AT START. MAINTENANCE GROUND BLOWER FAILED TO START. FURTHER INVESTIGATION FOUND A BROKEN WIRE INSIDE A BUTT SPLICE (AMP320559) IN A SPLICED SECTION OF THE WIRE HA8E CONNECTING LANDING GEAR SAFETY SWITCH TO WIRE H7CF IN WING TO PIN 6 ON HEATER BUSS BAR. SUBMITTER OBSERVED THAT BROKEN WIRE RUNS ALONG LANDING GEAR STRUT THEREFORE IS SUBJECT TO WEATHER, MUD, SNOW ETC. WHICH COULD SUBJECT THE WIRE TO PREMATURE DETERIORATION. AIRCRAFT HAD BEEN PRESSURE WASHED WHICH COULD HAVE BROKEN THE WEAKENED SPLICE. WIRING REPAIRED.