Chrysler Repair: 97 sebring coolant fan problem, upper radiator hose, coolant temp

Question
i have a 97 sebring jxi convertible and we just got it about 6 months ago w/ 125,000 miles on it...on july 4th it ran hot during a parade due to idling so long and ever since then we had problems with it so we got a pressure test ran on it and found out the quick disconnect hose was leaking so we got it fixed...that worked for 2 months and yesterday i noticed the overflow bubbling after an hour drive home while it was idling in the driveway...today it did the same thing while idling and i noticed that the coolant fan doesn't even kick on while the water temperature heats up but when i turn on the a/c the fan comes on...the temp gauge never riched hot but i could hear the overflow boiling from inside the car and i drive in a lot of traffic and the car idles a lot...any suggestions?...one other quick problem, my interior lights were going crazy while driving with the locks locking and unlocking and the car alarm going off at 3am in the morning and i read a previous post and realized that my passenger door if rattled causes the door ajar button to release so i put tape on the door to thicken it up and it worked but do you have a longer lasting solution...i didn't really see how to adjust the door latch ...please help me!

Answer
Hi Colt,
It is good that the fan works with the AC. The system is programmed to do that even when the engine is cold and you turn on the AC. Without the AC in action, the fan is turned on in response to the coolant temp sensor which is located next to the thermostat housing and which has a two-wire plug. (The dash temp gauge sensor is there too, but it only has one wire. All this assumes you have the 2.5L V-6 engine). The thermostat housing is located on the top of the engine near the front, the large upper radiator hose is attached to it.
I would suggest that you measure the resistance across the terminals of the coolant temp sensor. It should read 9-11K ohms at 77F and then drop smoothly as the engine heats up to 600-800 ohms when the temp reaches 212F* (gauge would be beyond half scale at that point). If the resistance doesn't drop down far enough when the engine heats up to turn on the fan, that would explain why you aren't getting the fan. So replacing that sensor should do it. Otherwise check the wires between the plug and the harness. The mixture is also controlled by the sensor, so maybe the engine will run better too if that sensor is at fault.
*Don't simply unplug the sensor with the engine running to make the resistance measurements as that also will start the fan; rather turn off the engine and check the resistance from time to time as the engine heats up.
The door lock 'striker' (not the latch mechanism in the door proper) that is mounted on the door frame has a couple of screws and if you loosen those, the striker should be moveable in-board which should cause the problem to be cured. You basically want the door to be secured tighter against the frame opening to stop the dinging/locking and lights going on and off.
Let me know if you still have a problem.
Roland