HELP e30 m3 s52 swap - Runs but - Coolant Temp Gauge not working... toltally stumped.

[r4esh]

"328ijunkie" (Dave?) - You rock. You were right... I had just convinced myself that there was no way it was a duel wire plug. I could have sworn on our previous swap it was a single wire plug. Sure enough the gauge works. Ultimately I hope this thread serves anyone have an issue with their temp gauge as thanks to everyone's support that is pretty much every possible solution / troubleshooting suggestion here. Dave as soon as there spare gauge comes I'll just send it back / wont even open it. Thanks again for looking out, you guys rock!
Man... it feels good to safely drive my car knowing I'm not cooking the motor!

[gath]

Bumping this back up. So the solution was to cut the ground (brw/ylw wire) at the connector?

[maclogos]

You shouldnt have to cut that wire for it to work. I have a 2 prong connector and use the M20 single prong sensor. My gauge works fine after installing a new sensor. I dont have a S50 but i do have the M50 and im sure the plug for that sensor is the same. At least from the pic i saw it looks exactly like my plug.