Quote Originally Posted by phonedawgz View Post
Get the 3 wire sender from a 98 Bonneville 3800 Supercharged. Top two pins (Black and Yellow) are the CTS. Bottom somewhat centered pin (Green) is the temp gauge. Hit me up if you need a pigtail and can't get one.

WIR425_ezr2.jpg
There are many 3100 and 3400 that use the 3 wire sensor as well.

FYI - The response curves for the stock CTS and the stock GM temperature gauge senders are different. They look similar but they are clearly different.
What? Everything I've seen says otherwise. The documentation I have seen have shown the resistance curves to be the same between coolant senders and sensors.