Chrysler Sebring 2003 overheating

[SamOfThunder]

My 2003 Chrysler Sebring is overheating.

A mechanic friend of mine is trying to teach me how to work on cars, and we redid the head gasket and ran into many issues, and this problem is our final barrier from having a brand new car essentially.

Fans aren't coming on because the ECM is reading the coolant temperature 60degrees off. Not sure what is causing the false reading.
Replaced thermostat (a previouse "mechanic" had put it in backwards), pushed air through the coolant lines, gets good heat, fans failsafe come on when AC is on, I can manually hardwire the fans on, but this is not ideal, I would like for the system to work automatically.

feeling helpless, no one seems to have encountered this problem.

[carriedi]

you need to check the accuracy of your coolant temp sensor. your low speed fan should come on at 220F and off at 210F, and your high speed fan should come on at 230F and turn off at 220F. (depending on the engine, there is a couple of degrees difference, but, generally) If you use an infrared temp gun at the thermostat housing and the computer and the temp gun are 60 degrees off you should at least check that the CTS is good or not. They are not very expensive. Replacing it would be cheaper than taking it to a shop and having them test it. And if it's not the CTS then if you take it to a shop you can tell them that it has already been replaced so they shouldn't need to look at that. They probably will anyways but you shouldn't pay for that if it's good. (every shop is different though)

other things that can cause the CTS to read wrong is resistance is a problem with the wiring or maybe a bad ground connection. You could read the resistance of the coolant sensor. at about 77F it should have a reading 9 to 11 K ohms. at 212F it should be 640 to 720 ohms. That's resistance across the two prongs of the sensor with the wire harness disconnected. If the sensor ohms out good you're going to have to check the resistance at the wire harness to the computer. Disconnect the computer connectors and see it the readings are still good coming through the harness. If it's still good you might need a computer.

[SamOfThunder]

Thank you! I replaced the ECT sensor and that did the trick!