What was found
LEFT SIDE WINDOW HEAT OVERHEAT ILLUMINATED. FOLLOWED QHR AND OVERHEAT LIGHT EXTINGUISHED. ACFT GROUNDED. PERFORMED FIM 30-91,TASK 89, WHCU BITE. MAINT MSG "P5-9/CONTROLL PWR" FAULT NOTED. SWAPPED WHCU'S. NO HELP. ORIGINAL POSITION RESTORED. INSPECTED C/B P18-3 POS D2 NO DEFECTS NOTED. CHECKED POWER IAW FIM TASK 30-91, TASK 813. AFTER REINSTALLATION OF WHCU. POWER RESTORED FOR LIFT SIDE WINDOW HEAT. GREEN POWER LIGHT ON OVERHEAT LIGHT REMAINED OFF. WHCU ON P5-9 PANEL, OPS NORMAL IAW AMM 30-41-11 AND 30-41-41. TECH SERVICES REQUESTS FOLLOW UP. R & R P5-9 WINDOW/PITOT HEAT MODULE REF 30-41-41.