2005 2500 auto stock 5.9 leveled on 35s


This is my first Cummins


I have read just about ever fan clutch post including some 4th gen ones but this issue seems to be a little different.


While waiting at the bank the other day (about 10-15 mins idle) I watched my temp go over the middle see attached photo. This was with the AC off, the truck did cool off after I started moving. The truck also did this while towing at low speed thru sand the fan did come on eventually but this was with RPMs. Is this normal behavior or is it time for a fan clutch (mopar) at 185,000 miles. I never noticed this when I got the truck last year (160,000 miles) Water pump was replaced shortly after I got the truck with mopar coolant. Radiator is clean. Note this issues only happens with the AC OFF. Now I am going to try this again with my obd scanner and read actual temp in numbers but unfortunately I cannot monitor fan speed with it. No codes, did get one when I unplugged the fan. Getting 12v and 5v to the fan. plug and wires look good.


Here is a brief history of fan/ac issues on this truck:


1. AC got warm upon inspection found compressor front main seal went bad found oil sprayed around the engine bay (could have also been silicone from the clutch)


2. New compressor/ac system serviced AC seemed to be all good


3. Couple months after the AC install found it to be spraying Freon out the compressor (high head pressure)


4. Eventually found burnt wires to ac compressor clutch (no insulation at all) fixed wires and recharged system about a month later no more frion leakage ac is working great and fan clutch does come on (seems to be a delay tho)


5. Towing temps seem normal (a hair under the middle) on the highway tho. The fan only seems to come on with the AC on. Could this be a ECM issue? Does the fan clutch have some sort of non electrical part as well like a regular fan clutch?


6. Getting ready to try the 55056990ac but really don't want to change it if its still good. Does any one know how their clutch operates with the AC OFF?

 

Sounds like a viscous fan clutch issue.
The fan was not running as designed at HOT IDLE.
It would run when its needed by ECM.

 

Well mopar fan clutch is on its way should be here sat, it also has a new cummins t stat.