So somehow a fan blade got broken off my fan??

And tore the wires from the fan clutch. Had the fan repaired with new blades by a local shop and they also "repaired" the dammaged wiring. A day or two later pick up the truck from the glass shop while getting my windshield replaced and the truck wouldn't start???

Lots of goofy codes present, cleared them with my scanner still no start.

Open the hood and start looking around, discover that the "repaired" wiring was once again torn off and wires touching the fan clutch. Move the wires away from the fan and was greeted by a shower of sparks as they touched the fan clutch or some other metal part.

Truck still won't start, cranks and cranks but no smoke, no fire.

Make an unhappy call to said shop and they come get it on their flatbed.

Call me a day or two later and say fan clutch has to be replaced.

They do so, haul a 15,000 lb load of water and truck starts to overheat until check gauges light comes on. But fan never engages.

Make another unhappy call to said shop and they say "likely deffective fan clutch" I doubt it....

Any ideas?

How do I jump the fan clutch to engage it to prove that it works?

Thanks for any help.

 

To engage the fan clutch. start truck, turn AC on high, cover AC condenser with towel. You will here the fan come on if its working.

 

Ground pin #1 will cause fan clutch to lock up.

VISTRONIC FAN DRIVE (DIESEL) - 6 WAY CAV CIRCUIT FUNCTION
1 Y1 18LG FAN SPEED CONTROL
2 K4 18BK/LB SENSOR GROUND 1
3 Y5 18OR FAN SPEED SENSOR
4 - -
5 Y3 18WT SENSOR SUPPLY
6 F15 20DB FUSED IGNITION SWITCH OUTPUT (RUN)

 

Thanks very much, this is likely a dumb question but how do you ground the pin? Do you have to piece the wire?

 

Pierce that was.

 

ELECTRONICALLY CONTROLLED VISCOUS DRIVE - DIESEL


You can fabricate a back probe tool from paper clip, wire, alligator clip. or spend big bucks on this miller tool. Make sure the fuse hadn't blownyou should have 12 volts at pin 6 fan connector. Powered by fuse #4 in the TIPM (PDC)
https://millerspecialtools.service-s...l.aspx?id=1663


If the fan assembly does not free-wheel and a metallic grinding sound exists, replace the electronically controlled fan drive (Refer to 07 - Cooling/Engine/FAN, Cooling - Removal) .



NOTE: The following test may take up to 15 minutes to perform.

The engine should be at normal operating temperature.

1. Set the parking brake and verify the transmission is in park or neutral.
2. Set air conditioner (if equipped) and blower fan to OFF.
3. Start and allow engine to reach normal operating temperatures.
4. Stop engine, connect the scan tool and select appropriate model year and engine option.
5. Check for and correct existing DTC's
6. Using Tool 6801 , backprobe pin 1 of the electronically controlled viscous fan drive connector, with the harness connected located at the lower fan shroud to battery ground.

NOTE: The fan drive control coil is energized to 12 volts at this time.

WARNING: A spark may occur when connecting pin to ground. Be sure that no combustible material is in the area.


7. Using the scan tool, verify that DTC 0480 set. If it is not set, verify that a good ground is available.
8. Start the engine.
9. Actuate engine speed to 2000 RPM.
10. Go to the SENSOR screen and observe the fan speed.
11. Run the engine at 2000 RPM until the fan speed increases to 1850 RPM or more for 30 seconds.

NOTE: Fan RPM may ramp up slowly.

NOTE: It maybe take 15 minutes before fan speed increases.
12. The fan speed should be in accordance to the table below.
13. If fan speed does not increase, make sure that the jumper wire has a good connection. If so replace the electronically control viscous fan drive.
14. If the fan speed does increase and there is still a concern, refer to the appropriate Engine Electrical Diagnosis Section to diagnosis the electronically controlled viscous fan drive control circuit.



ELECTRONICALLY CONTROLLED VISCOUS FAN DRIVE SPEEDS
ENGINE RPM FAN RPM (Min)
1000 950
1500 1420
2000 1850
2500 2230