Electromagnetic Clutch Fan Temp sensor

[Tomas]

After a new radiator and purging all air from the system a few times the engine was still getting hot. Noticed the fan does not engage after 205 degs. Two cables go to the magnet clutch on the fan. On2 is a ground wire and the other supplies 12V. When applying 12V directly to the power wire the fan will engage so it is not a clutch problem.

There are 3 temp probes / switches on the head. The one on the exhaust side closest to the radiator has two leads and is used for the temp gauge on the dash. The one behind one has one lead and I don't know what it is for. Anyone know? The one on the intake side of the engine gets a 5V signal and from what I've been reading this should be the sensor that tells the ECU to engage the fan which then sends 12V power to the electromagnetic clutch. I measured and it does get 5V. When I bridge it however, the fan will not engage.

Is this an ECU malfunction? What else can I do outside of using a manual switch to activate the clutch?

[cadillackid]

the single lead may be for the engine temp alarm.. or is it possible that one is your fan clutch?


the ECU one is a 0-5 volt signal, shorting it out really does nothing other than make the computer throw a code.. its not a switch its a resistance sensor..



im not sure on that bus how it works.. there is likely a relay smeplace that the ECU calls for which in turn engages the clutch


is there a popped fuse some place? its unusual to see the computer supply 12 volts.. usually the 12 votlts is already there and the computer supplies groud.. however again im not familiar with your chassis

[AlexLasVegasBusSales]

Message Me a picture of you fan clutch I can help you

[Tomas]

Originally Posted by cadillackid

the single lead may be for the engine temp alarm.. or is it possible that one is your fan clutch?


the ECU one is a 0-5 volt signal, shorting it out really does nothing other than make the computer throw a code.. its not a switch its a resistance sensor..



im not sure on that bus how it works.. there is likely a relay smeplace that the ECU calls for which in turn engages the clutch


is there a popped fuse some place? its unusual to see the computer supply 12 volts.. usually the 12 votlts is already there and the computer supplies groud.. however again im not familiar with your chassis

I will try to find the relay.

[Tomas]

Originally Posted by AlexLasVegasBusSales

Message Me a picture of you fan clutch I can help you

Thanks. Here you go.