i have a 03 cummins that keeps overheating anytime i put weight behind it. i replaced the wp, thermostat, belt, clutch fan and many other parts. the fan wires were cut like normal and fuse was blown. replaced the fan and fuse and it wont turn on still. getting both codes for the fan, fan speed and fan voltage or whatever. fan wont come on with ac either like everyone says it will. any help anyone? i cant find anything and need this fixed because i tow with this truck almost every day. thanks

 

When it's running take the radiator cap off "carefully" and look in the coolant if you see little bubbles coming out constantly you have a blown head gasket. Most likely case! Even without the fan when driving it shouldn't get hot!

 

How hot is it getting? Is it only when you are pulling a load?

 

Usualy I won't hear my fan unless I am towing a heavy load in 100 degree temps. And that was on all my dodge diesel's 2000,2004,2006,2010.

Your right you may have a fan problem but a dirty intercooler,radiator could be a factor to your problem.

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That too can be a cause and easy fix! Mud packed grill area! Man that would be much better than a blown head gasket!

 

yes its only when towing. its weird because everyone i talk to says it cause the fan isnt coming on. i cleaned everything and nothing. a guy on another forum said to ground the ground wire and it will lock up. guess im gonna try that. im starting to think my ecm got messed up when the wires got cut if they touched eachother aqnd shorted something out?

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if i dont watch it it will peg the gauge. i normaly notice it when the gauge gets to about 220 and pull over. dont want to melt down the motor. i know you wont always hear the fan because the ecm locks it at percentages to cool it at certain temps. all i do is tow with this truck so its a prety big problem.

 

did you check for bubbles?

 

my did the samething replaced all the stuff you did, cleaned outside and power flushed the inside of radiator still was doing it. finally i bought a radiator from genesis outo($150) on the web problem solved. cut the old radiator in half and 75% of the inside was completly clogged. it only over heated when towing, hope this helps

 

Is it a Cummins T stat

 

My radiator was pretty clogged up as well. When I changed out my rad and put in a cummins t-stat and the cooling problems went away.