Hey everyone have a question, so I have a 94 Del Sol Si and I noticed that the cooling fan is always running from the time the car starts until it is turned off and I cannot figure out why. To chase the issue and do maintenance that was well over do here is a list of parts that where replaced
Thermostat and gasket (170 degrees)
cooling fan switch
aluminum radiator
cooling fan
upper and lower hose
coolant

I also removed engine temp sensor but assume its working because I get a reading on the gauges so I cleaned it and reinstalled, Also I would imagine that my relay is working correctly because when I remove it the radiator fan turns off but turns right back on when relay is reinstalled (also tried 4 other relays that I know are working and still the same outcome)

So my question is this, What could be causing the fan to constantly run? I would think, like my other cars that I own that the fan comes on as needed when the engine temp gets hot enough. I bled the coolant last night 7/1/22 and I am getting heat from the vents ( I unplugged the relay to build engine temp) and to my knowledge car is not overheating and wiring seems to be ok as well the factory harness has not been tampered with and the wiring to the fan or the fan sensor. Everything is OEM so what could make this happen am I missing something or forgot to check something? PLEASE HELP!!

 

The fan switch (on thermostat housing) or the ECM are what can trigger the fan.

Unplug the connector to the fan switch, then turn the ignition to ON position (car doesn't need to be running). Does the fan still run?

 

ok i just unplugged the new fan switch and i turned the key and the fan runs weather the fan switch is plugged in or not

 

yes i have tried that i have swap relay and used other known working relay and same result

 

OP, based on your statements above, you have one of two issues: 1) The wiring for the plug at the cooling fan motor has been altered to run constantly when the ignition switch is turned on. 2) The green wire in your fan switch plug is damaged somewhere and is grounding out. This would activate the fan relay when the ignition is turned on as well.