Inaccurate Temp gauge

I have a 1995 Transsport hat I have owned for about 11 years. All through this time, the temp gauge has consistely read about 20 gdrees C below engine temp. Just did some engine work and replaced temp sensor at that time, but no improvement. PCM scan indicates engine running at between 195 to 205 degress F, yet gauge nowhere near that. When lead jumped to ground, gauge deflects to max as it should. Good continity between sensor and connector beside battery, and pins in connector look sound no corrosion. Ground on engine, front rad support and side fender all cleaned and tight. All other gauges and instrument panel functions proper, just this gauge inaccurate. Any suggestions where I may look to find the higher resistance? Anyone else have the same problem? Thanks
Jeff

Engine type? (best is indicate in your profile...)
Which sensor was changed? Instrument or computer? The one near the thermostat is the computer's. The instrument's sensor is farther back..hidden.
www.avigex.ca/xport/instrumentpanel1.jpg
www.avigex.ca/xport/enginesensors1.jpg
www.avigex.ca/xport/thermistor.jpg
ON the other hand, I've never considered this vague gauge calbration to promise absolute value: rather relative "information" allowing to see changes from normality....; mine indicates low also...I think.

LMP:
Thank you for the resistance table, lot better than the couple that the manual shows. Looks like only a couple hundred ohms between what I have and what I should have. I am confident the problem is moreso in the engine wiring side than the instrument panel side, so will take a measurement from the 10 pin connector to the sensor and see what it shows. While the sensor is new, I did not run a tap through the threads to clean the head, any idea what size is used? Also, how do I update my profile? BTW, it is a 3.8 engine, thanks
Jeff

Yeah...to go to the profile , click the "private message" link at top right, and then on the left, you have control panel, profile, garage setting...etc.
...and which of the two temp sensors did you change? ...

It was the gauge sensor ( single wire ) that was replaced, believe pcm sensor still original. Hope to get further readings this weekend.
Jeff