Fan turns on too often.

[93STLTH]

My radiator fan cuts on and off a lot. Seems like the temp sensor might be bad (or maybe something else?) I've looked at my manuals and there seems to be at least 2 sensors and 3 relays for the fan. What should I be looking for? The problem isn't with the temperature, it stays steady all the time. It's just the sensor or the relay that is running the fan too soon or incorrectly.

[Alex3000gt]

My radiator fan cuts on and off a lot. Seems like the temp sensor might be bad (or maybe something else?) I've looked at my manuals and there seems to be at least 2 sensors and 3 relays for the fan. What should I be looking for? The problem isn't with the temperature, it stays steady all the time. It's just the sensor or the relay that is running the fan too soon or incorrectly.

Hm..

First gen fans are controlled purely by the temp sensors at the bottom of the radiator. It is a simple resistive element that is open circuit at low temps and closed circuit at high temps.

Cheap to replace too.

[93STLTH]

Thanks Alex! I didn't find that in my shop manual. It was talking about sensors in the engine bay and another one that I couldn't even figure out by the diagram.

[GTOJOE]

93 could be using the 2nd gen configuration. 1st gen has 2 switches with built in sensors both mounted to the radiator. 2nd gen has temp sensors that feed back to the ecu. The ecu then turns them on or off. You will probably need to compare the sensors on radiator to confirm your setup. Also climate control will turn the ac fan on when ever ac is on. Without ac on that fan will only turn on when very hot.

Sent from my GT-I9300 using Tapatalk 2

[Alex3000gt]

93 could be using the 2nd gen configuration. 1st gen has 2 switches with built in sensors both mounted to the radiator. 2nd gen has temp sensors that feed back to the ecu. The ecu then turns them on or off. You will probably need to compare the sensors on radiator to confirm your setup. Also climate control will turn the ac fan on when ever ac is on. Without ac on that fan will only turn on when very hot.

Sent from my GT-I9300 using Tapatalk 2

Also true. I would log your temp sensor using MMCD and see what you find out. Missed the "93" in the username! :)

[n2nsanity]

Probably about time to replace the sensors anyway. If you have 2 on the bottom DS of the radiator, that's the 1g setup. If you have 2 on the water housing, that's the 2g setup. For $10 or so each, can't hurt to go ahead and replace some the 20 year old sensors, lol.

[stealthee]

93 still uses the sensors in the rad.