Cooling fan
 

Adjusted valves on 1990 Camaro 305 and what I think is knock sensor got broken. It's located in right head between plugs #6 & 8. The fan didn't come on when temp got high and I took it to a friend that does some work on it. He said it's the temp sensor but I don't know. If a/c is switched on the fan comes on, so it worlks. Wondering if the sensor broken is part of problem w/fan not turning on with high temp. Please help diagnose....

It´s the cooling fan temp switch that is located between 6 & 8 plugs.
Knock sensor is low on the block above the pan rail.

cooling fan switch
 

Thanks for the info. I read where the knock sensor was in the block but didn't see it. The fan switch makes sense as the fan sisn't come on until a/c was switched on. Thanks for the info