Hi Boys!
Thanks a lot, found it. I searched somewhere in the enigine, but now I found it...
Now I have an other problem. I bought my temp gauge at Agriline in the UK. It came with a thread:
and an adapter for a bigger thread:
which looks like this in the end:
But now my Problem. There was a sensor screwed in which looks like this:
The new thread (original) is to small. The adapter is to big...
What can I do now? I don't want to make a bigger hole in the engine... Tried also to buy a new adapter but no shops in my area offer one...
How does the gauge works? Is the temperature transfered to the gauge only by the small wire inside? Will it work if I cut the new sensor and fix it to the old one? Or will the new gauge breake after this?
Thanks George
. The sensor in your first picture is what you should have. What you are saying George is that the adaptor thread is larger than the hole in the housing? Can you measure the small nut and see if it fits into the hole. Something does not look right there 
. The water temp gauge that I have does not have a bigger adaptor nut and the smaller nut looks similar to that of yours. Could that gauge not be for a Fordson Major 
. Hopefully someone with a Major might be able to put some light on the issue. Maybe you should contact Agriline and explain it to them. 