I am wondering if my fan clutch is working properly. Any ideas on how i can test it or find out if it is fully engaging or not. The truck is to loud to hear if it is going on or off while i am driving.

 

sitting still idling does your temp rise real high or stay normal

 

shake it forward to back like firewall to radiator. there should be no play in it

 

sitting idle and driving the temp is fine but as soon as i climb a hill it gets hot. I am going to put in a new thermostat but i wanted to be sure the fan is working right. I think its the thermostat because one time while pulling a long 9% grade with a cord of firewood in the back it was getting hot then all of a sudden the temp dropped to almost normal and i had not finished climbing the hill yet.

 

pull your thermostat out, its very easy, and drive it. if it stays way cool its your thermostat, if its still getting hot you got a problem somewhere else. and DO NOT buy a thermostat from napa or oreilly or any of those places. a cummins thermostat is a MUST. trust me i learned the hard way

 

I checked that and there was a very small bit of play but just barely anything.

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Ya thanks to this great site i new ahead of time so i got the cummins t-stat for $35 at the local cummins shop instead of paying the local dodge dealer $125 for the one they had.

 

good choice. the other auto parts ones are junk and dont work or fit right most of the time. especially on the first gens, theres a slotted keyway they have to go into and the aftermarket ones dont even have that

 

Are you the original owner, or did you buy the truck used??

 

I bought it used. I sure wish i had got it new then i would know all the history. Its got 220,000 miles now.

 

I recommend replacing it the same time as the t-stat. That way your ready for the months ahead (late spring to early fall). Might also be a good idea to have the coolant tested, inspect all the radiator/heater hoses, belt, and the inside of the radiator (corrosion, plugged tubes).