help with temp gauge

1986 GT. The temperature gauge is not responding. It moves when I put the ignition on but stays indicating cold even when the engine is hot. I located the temperature sensor switch on the front left side of the manifold just below the ignition coil that when grounded activates the temperature idiot light on the dash. The solid green wire. It also has a green/white with it that seems to do nothing.Where is the temperature sensor that grounds the temperature gauge. Can you help?

under gooseneck for thermostat. one single green wire with a white stripe, is for temp guage.

under gooseneck for thermostat. one single green wire with a white stripe, is for temp guage.
Thanks...turns out that one is the switch for the fresh air blower on the alternator and the ignition coil. I found the temp gauge sensor is the same as the idiot light switch. The second wire was the gauge one, there was a break in the wire just before the connector. I finally fixed it. I appreciate your help. I will most likely be back in the near future with more questions.