After replacing the fan clutch for the 2nd time in 2 weeks, I'm still getting the P0480, P0483 code. I can literally stop the fan with my hand while the engine is running. Pulling heavy loads the engine temp will climb up past 210 and the fan will not engage.

Any ideas what to look for?

 

I can stop the fan with my had too, it's normal. So is the fan not engaging at 210°. The 190° thermostats don't go fully open until 207° so 210 is not really that hot.

The only time I have heard the fan engage from heat (not a/c) my coolant was about 218-220°. I can hear it cycle at a lower temp if the a/c is on, but not full on. I can pull grades at 213-215° and not hear the fan come on. I have had my fan checked and have no codes.

Did you clear the codes with the new clutch installs?

 

On the first fan clutch I cleared the codes. Within a week the codes were back so I installed the second one. Drove it today and the temps starting climbing around 210-212, those temps seemed a little high for me.

 

Depending on the load and ambient temps those coolant temps may be normal.

Are the codes back? Did you clear them after the 2nd install.

Do the wires on the block look like they are in good shape?

 

Temps have only been in the high 60's to low 70's. Water pump is working just fine and t-stat seems to open up right at 192. Grounds to the block look great to..

I had a similar problem last year with the crank pulley sensor. It just stopped working for no reason. Took it to the dealer and they said the ecm was not sending the proper signal. They ran a new electric line from a different ecm port and everything worked great. They warmed me that my ecm maybe on the brink. Kinda has me worried that the fan clutch might be the same.

 

Your temps really are nothing to worry about. 225° is the max allowed by Cummins when running a 190° thermostat.

Are you out of warranty?

 

Yep.. lost that about 70,000 miles ago.

 

If you think there might still be an issue, pull the connector apart and look at the pins, maybe one got bent over and isn't making contact.