Does the coolant temp sensor and sending unit work together, The sending unit works with the cluster on the dash, what does the sensor do? and if my dash gauge reads higher than normal and drops back down SOMETIMES how can I be sure its not temp a gauge issue?, Ive replaced the temp sending unit with one from AZ, im not too sure if these are of quality...

 

I am not sure, but I have always been under the impression that SENDING unit (on the side of the engine just sends the temp of the engine to the instrument cluster white the Coolant temp SENSOR is actually a switch that closes and lets the radiator fan come on. But I am not sure. I switched over to a mech. fan years ago because I got tired of messing with my electric fan not to mention it did cool the radiator like I needed with an engine swap.

 

They are two completely separate things. The sender in the driver side head is for the dash temp gauge, The CTS in the front of the intake manifold next to the thermostat cover tells the computer what the temps are to control the engine. The fan switch in the passenget side head turns on the fan. AZ sender should work OK, but needs to be the correct one "for the temperature gauge"

 

Thanks mines been doing some freeky things Im gonna try to get a OEM one thanks