The best manual is the Chrysler service manual. They come up on eBay every once in a while. Make sure you don't buy the one for the coupe, which is a totally different car.
The Chrysler manual has all wiring diagrams, etc. It comes in several volumes; you'll at least want the main manual and the convertible supplement.

Aftermarket temperature sensors tend to read a little lower than OEM ones, as has been discussed here on the forum several times. Now that you have spun the sensor insert in the plastic housing you can be reasonably sure that it will start leaking.

Yes, that sensor is the source of information for the computer that controls the fans.

Make sure that the radiator is not plugged both externally and internally. Either can be a cause of overheating.

The car is now 9 years old. If the A/C is not working it may need some attention. You didn't say what the ambient temperature was when you tried it. If it's too cold out it won't kick in.

Flickering oil light may be indicative of a sensor problem. Change the switch and see if that fixes it.

 

Thank you dcotter. Found set of 5 manuals on ebay (service, chasis, body, powertrain and trans, but no convertible supplement)

With aftermarket sensors reading low, will that make the car run hotter before the fans kick in?

I originally thought one fan went on and then the other, but found they both go on at the same time, but with low and high speeds.

I ran the car until temp gauge read 1/8, unplugged the sensor and the fans went on and the gauge went to zero. Seems fans are okay. Also jumpered both relays and both speeds worked.

I ohmed out temp sensor when cold (26.6k ohms) and when gauge was at 1/8 (1.6k ohms). Any idea what resistance should be to make gauge read 1/2?

It was cold when I tried the a/c. Will check it when it gets warmer.

Where is the oil sending unit located on the 2.7? and what is a normal pressure?

 

Well, your test of the sensor confirms that it is doing what it is supposed to do. The resistance is supposed to go down as the temperature goes up. I don't have any idea what the "correct" reading is for a mid-range gauge indication. If you're curious about it you could put a rheostat in parallel with the sensor and dial it down until the gauge got to mid-point and then measure the combination, but it wouldn't ultimately accomplish much to do so.
As for your question about will the fans now be coming on at a higher temperature, that would be a logical conclusion since there is only one source of information for the computer regarding coolant temperature. I wouldn't think ten or 15 degrees (if it's even that much) would make any great difference in the vehicle operation. On my 2002, purchased new, the gauge always read around the 1/3 to 3/8 position.
You could try replacing the sensor with a part from the dealer. Since the female part spins in the housing, you'll be replacing the housing too. If you look around, you will find aftermarket housings available without a sensor. They are much cheaper than the dealer part. I think the housing is sold by the dealer with a sensor. I don't know if the dealer sells the sensor without the housing.
Keep looking for that convertible supplement manual. They come and go.
The body, powertrain and transmission manuals are diagnostic manuals. Actual repairs are covered in the service manual.
Fans coming on when the ECT sensor is unplugged is how it's supposed to work. That's a "fail safe" design, meaning when there's a failure, it goes into a safe mode.