What was found
DURING APPROACH FLAP 1 SELECTED L/E FLAP TRANSIT LT ILLUMINATED ON AND OFF. FOLLOWED QRH PROCEDURES LANDED AT FLAP 15 STILL HAD L/E FLAP TRANSIT ON FORWARD PANEL ILLUMINATE APPROACH SPEED WAS 149 KTS LANDING NORMAL. PERFORMED TROUBLESHOOTING PER FIM 27-88-00-810-805 FOUND NR 4 FLAP RETRACT SWITCH AT FAULT R& R''D PER MM 27-88-00 BITE & AMP; OPS CHECK GOOD REF ER TO L/P 8131226 FLAP OVERSPEED INSPECTION.