Truck Repair: 91 Pete 379 Big Cam 4 mechanical Cum., fuse panel, fan clutch

Question
Cooling fan not activating by high coolant temp, only by manual toggle switch.High temp buzzer and light activate but not fan clutch. Is there a relay for fan if so where is it located? Thanks

Answer
Any relays will be in your fuse panel. Been along time since working on a older truck but heres my thoughts. you know the shutoff solenoid is working because you flip the switch and the fan works. You know your temp sensor is working because its showing you that on your dash. So my thought is you have either a relay blown or you have a wire rubbed between those 2 circuits so would see if there is a relay if not trace your temp sensor wires and your solenoid wires til you see where they come together at.