Chrysler Repair: 1999 Chrysler 300: are fan(s) non-functional?, coolant temperature sensor, temp gauge

Question
I was stop for a while with my engine running and I notice
my heat gage went up. I think my fan doesn't work. After I
drove my car for a while the temp. went down to normal. I
need to know how to fix it myself if possible.
              Thank You  Jerry

Answer
Hi Jerry,
The mere rise of the temp gauge may not mean there is any malfunction; these gauges are not necessarily accurately calibrated. I would suggest that you turn 'on' the AC or the windshield defoster setting of your AC/heater control panel, with the engine running of course; then open the hood and observe whether one of the fans is running. If it is then the fan control circuit is OK.
Then when you are driving the car on a warm day, stop and let the temp rise above half scale, open the hood and again observe the fans. If they aren't 'on' let the temp rise higher until one of them comes on. If a fan doesn't come on when the gauge is nearing full scale then you have an issue with the coolant temperature sensor not getting a signal to the engine controller to turn on the fan.
It could be the sensor or the wiring of it to the engine controller, but until you do these two tests to check the function of the fans' control circuit and the function of the coolant temperature circuit, there is no basis for concluding that something is wrong. So let me know if you fail either test, and we'll go from there.
Roland