What was found
BOI FLIGHT NR 2320: NR 1 BLEED HOT CAUTION LIGHT ON AFTER START UP. TURNED OFF BLEED SWITCH PER CHECKLIST AND CAUTION LIGHT STAYED ON. MAINTENANCE REPLACED NR 1 PRECOOLER TEMP SWITCH IAW AMM TASK 36-11-11-000-801 AND 36-11-11-400-801 AND NR 1 BLEED OVER TEMP SWITCH IAW AMM TASK 36-11-16-000-801 AND 36-11-16-400-801. GROUND RAN AIRCRAFT AT VARIOUS POWER SETTINGS AND BLEED SETTINGS FOR 30 MINUTES. NO BLEED CAUTIONS. CHECKED CDS FOR ECS FAULTS. NO FAULTS NOTED. AIRCRAFT RETURNED TO SERVICE.