Ok....found the chart and everything looks good with resistance checks at certain temps. I checked for input voltage supplied to ECT and it had about 4.9V...which I assume is correct. I also scanned the codes and they were P0116, P0115, P1116, etc.. they all indicated ETC problems.
After these checks, the gauge is starting to work now. I assume a loose or dirty connection that I "repaired" by fiddling with it BUT the engine light is still on. I disconnected the battery for 20 secs. and the engine light still stays on. I guess I'll have to go to the store and rescan my codes now....
On a side note...I noticed when the temp gauge stopped working, I noticed that the Voltage information on the digital instrument cluster only read 12.8 V. I put a meter on alternator output and it was a normal 14.8V. So there was a big discrepancy. Now that the temp gauge started working, the Voltage reads 14.8 on the instrument LED cluster, which matches my meter perfectly....
Thanks