What is the resistance of the fan temp switch

Might have got wrong temp switch. Ive had switches that look the same but internals are different( resistance values). Best bet is to get OEM sensor.

Sounds like you did a good job checking the obvious areas. The next steps are to check the cooling temp sensor and the fan switch. Use a multimeter to check resistance at both cold and hot temps.If the switch is open at COLD, it should close when HOT in order to activate the fan. If it remains open all the time, you need to replace the switch. You can bench test the switch rather than trying to test it mounted in the engine.

check that you have a thermal switch to switch on the fan and not a temp sender unit. One completes the curcuit when a set temp is reached ,the other is a resistance unit that lowers the voltage which in turn reads hotter on the gauge.

Some cars have a thermostat that tells the fans when the water temp reaches a certain temp then the fans start. Or the relay that starts them could be bad. You may find the relay and switch it with another like it and see if that works.

relay stuck on

If the fans don't engage after the engine reaches normal operating temperature start the diagnosis by checking the fuse 16 under the dash, and fuse 4 under the hood. If those are good test the coolant temperature sensor by checking the resistance across the two sensor terminals. If the coolant temperature is 50 degrees F then the resistance should be about 5670 ohms the resistance increases at cooler temps and decreases at higher temps. If the sensor is good then have the fan relays tested. Since both fans don't appear to be working the fans are probably ok.

You found the problem, bad coolant temp. sensor, replace it and it's fix.Hope this was very helpful.

there is'nt a sensor for the clutch fan. with the engine off there should be some resistance to the fan hot or cold. if there is not the clutch is bad. also check when the engine is running if there is any wobble in the fan blades. if there is it's bad and you need to replace asap. they can come off, bad news!

The 2 AC fsnd turns on when the Engine temperarure hot. It receives the signal from ECU throught the Engin temperature sensor ( Coolant). Your case happens since the Engine Temp sensor went bad. At beginning the temp sensor can not produce any resistance just like open then ECU thinking engine hot turns on the Fan. When your engine ia about 85, it is a normal temp then the sensor could produce some resistance matching the look up tabel for the ECU, then the ECU turn off the Fan. Some pepople has it run all the way since the wire contact to the sensor was off. Replace the Engin Temp sensor to take care of the problem.
You have 2 temp sensors on top engine, one for your temp read out, one for the fan purpose. If you don't know which one, wait for your temp at 85 and the fan is stopping, then unplug one, imediately the fan goes on, that the one. Good luck.

check your relays disconnect and look at the switch is open and one is closed ...check the resistance with ohmeter....one should be open...ones should have resistance..that is the switch...then check sensors.. you can disconnect and boil them, to see if the resistance changes when under high temps 160-200 f should show resistance changes...check main computer relay as well sometimes the cooling fan electrical curcuits are shared in the system multi plexed...