EM Klutch Fan - Benzworld.org

**Jippi** · 09-26-2006, 11:32 AM

ok this is real weird. i had problems with the fan not turning on when the car hits the rite temp. i warmed the car up to about 100 degrees or so and measured the voltage at the klutch connector near the t-stat. theres about 12-13 volts going in to the em klutch but the fan is not turning on. so naturally i thought the em klutch was broken, but when i connect the em klutch directly to the battery it works. so where is it going wrong? theres 12 volts going into the klutch at the rite temp but the klutch isnt kickin on where am i going wrong? i put a working klutch in and same thing. whats the next step i should take?

Jammerkiller · 09-26-2006, 03:50 PM

If there is voltage at the connector, but it only works when you straight wire it to the battery, then it may not be getting enough amperage. You could have a reading of 12-13 volts, but it may be weak. Also, shouldn't the voltage be around 13.6? Maybe the voltage regulator in the alternator is going bad and can't supply enough current to the clutch. How is your battery charging status?

fbotros · 09-26-2006, 05:33 PM

Your fan clutch switch is bad, it's a 3 pin switch located on the head. part #0065456124 or #0065459124 (double check which one). The Aux fan should come on at 120 degrees but you shouldn't drive the car.

jmas2k · 09-27-2006, 08:44 AM

When the ignition switch is on, there is always voltage present at the Positive side of the clutch coil because the EM fan clutch works by grounding the Negative side through the temp switch. Short the correct 2 wires at switch and if the clutch coil is OK , the clutch will engage. Then the swich is probably defective. The switch should close at 100 degrees C.

**Jippi** · 09-27-2006, 02:43 PM

wait jmas. when the switch closes it should get 12 v power and not a ground, im pretty sure of that. if i recall correctly, the switch i have is a 100/110 switch. the aux fan comes on at 110. like i said when the car reaches 100 deg it switches so that there is a 12 volt signal at the klutchs pos wire. but when i get time i will check the cars charging system. rite now i started classes and dun have the time i use to have.

**Jippi** · 09-30-2006, 03:47 PM

ok well i measured it and at the sensor the common wired of the switch is geetinf 11.8 volts and the klutch is getting 12.6 volts or so. the battery is getting 13.8-14 volts. where does the sensor common side get its power from? and what could be causing the sensor's common side not to get enough power. the alt is a bosche reman piece.
thanks

**Jippi** · 10-18-2006, 11:35 AM

well i got brand new sensors and relays and it soes the same thing, theres not enough voltage getting to the em klutch to allow it to kick in by itself. i also put in a new battery and a check over the electrical work i did when i fixed it and is fine. anyone have any idea of what can be causing the low voltage to the em klutch.??

Yal · 10-18-2006, 01:52 PM

I think you should let it continue to get hot. It should kick in a couple of mm above the 100 mark.

**Jippi** · 10-18-2006, 04:00 PM

the sensor switches and theres 12volts going into the clutch but the clutch doesnt come on. few minutes later the aux fan iin front on the rad kicks in. but the voltage going to the em klutch is a little less then 13 volts.

Yal · 10-19-2006, 07:11 AM

Ok so how do you feed battery power to the clutch to get it to work? Do you take the wire from the sensor and feed it 12v from the battery? Is it possible that the wire from the sensor to the clutch is bad? Run a new wire from the sensor directly to the clutch and see if that kicks in the fan when the sensor switches.