I own a 1997 Acura TL 3.2L V6 with 150,000 miles. Following your guide, I replaced a cracked radiator and reattached the two electric fans. I am now having inconsistent temperature readings. A majority of the time, my gage reads normal temperature, and the fans will run as needed. When my car begins to overheat however, I have noticed that neither of the fans is running. I have checked both fan motors which are operative, and the fluid level in my radiator which is full. It has been suggested to me that I need to check the Fan Relay Sensors, and potentially the Coolant Sensor. How do you check the Fan relay? Is there a way to determine if the coolant sensor is faulty/ malfunctioning?
The CTS provides an engine coolant temperature input to the ECU, which will then enrich the air/fuel mixture delivered by the injectors when the engine coolant is cold. Based on the CTS signal, the ECU will also control engine warmup idle speed, increase ignition advance and inhibit EGR operation when the coolant is cold.
Disconnect the wire harness connector from the CTS and measure the resistance of the sensor with a high input impedance (digital) volt-ohmmeter. The resistance should high when cold and be less than 1000 ohms with the engine warm. No reading at all-defective
Checking the relay you have to remove and test the coil and switch side. The coil side should be about 80ohm and the switch side will read infinite. any reading other then this -replace it.
Beware they are 3 -different types of auto relays-it should have a picture on the relay, showing the coil and switch side.