Tempreature

[taco]

Hi

I got a mk2 79 eksi love it to bits thats why i threw out the old engine and went up a few sizes. Just having problems getting the temp gauge to work went to purchase a new sensor but the size of the thread was about 5 mill to small soi found a sensor with the right size thread and it doesn't work. i know ive got the right wire becuase if i short it the gauge moves. any hints would be appreciated greatly.

thanks