Cubhauler

I'm trying to figure out what type of fan clutch I have on my '03. Dealer tells me it is a vistronic, mechanic tells me it's a viscus clutch, does anyone know for sure?

vzdude

5.9L DIESEL
The Engine Control Module (ECM) controls the level of engagement of the electronically controlled viscous fan clutch by monitoring coolant temperature, intake manifold temperature, air conditioning pressure and transmission oil temperature. Based on cooling requirements, the ECM sends a signal to the viscous fan clutch to increase or decrease the fan speed.

Fan speed is monitored by the ECM. Fan speeds above or below a calibrated threshold will set a DTC. Circuit concerns will also set fan clutch DTC's.


Clear as mud huh? LOL But they are both correct actually. It is electronic, and it is viscous.

Cubhauler

Thanks for the info, I talked with the mechanic at the dealer I was delivering a transmision to today, he filled me in on where to check for broken wires and such, does anyone know if I could just wire it into a switch so I could control it manually?

vzdude

I don't think so . I can't remember who, but someone on here was trying to do that as well. IIRC, it is a pulse modulated signal that would be hard to reproduce with any kind of a switch.