Engine fan wont turn off

[Chamberpains]

(03-30-2020 )amermextrucker Wrote:  Ended up being a rotted cable in main harness that goes from solenoid to ECM. Parts was $10.00 and labor and diagnostic was $ 490.00 . LOL.

There is no way I'd LOL at that price. I'd be pissed. I would kick myself in the ass so hard to learn how they diagnosed this problem so I would NEVER pay someone $500 to fix a wire.

Some help in future situations for guys that want to learn is to have Cummins Insite or what ever diagnostic software you need. If you dont have it, spend the money, do the research and go get it. The next step is to see what sensor or circuit is failing or not reading correctly. Then finding the steps to test the sensor or circuit. For Cummins (and why Cummins is the best to own) https://quickserve.cummins.com/info/index.html is free and will have the troubleshooting trees for most diagnostic procedures to find if its the sensor or circuit and what to replace or repair. And the last tid bit I can give is if it's not the sensor or solenoid and points to wiring, then don't be afraid to physically grab the wires, cut the zip ties loose, pull the loom off and keep chasing those wires searching for rubbed points, broken, exposed or bulged wires, bad, corroded, poorly connected or pushed back pins in connectors.

When I worked for a dealership years ago, I'd get trucks that guys would spend multiple 8 hr shifts (which the customer would pay for that time) trying all kinds of diagnostic acrobatics "trying" to find intermittent or on going problems only to shrug their shoulders and say nothing is wrong or they give up. Never even looking at physical wires or plugs or only looking in the easy spots to get to. Then to have me get head long in to it by ripping the harness out and physical search the wires and find it was rubbed or visibly bad somewhere hard to get or just wasn't looked at.

Doing this style of physical searching also usually reveals A LOT of other problems or potential problems that can be fixed. It's usually never bad to get dirty and climb all over your equipment like a snake. It gets you more familiar with your equipment and that is priceless information for the next problem that is bound to happen.