How to test 3 wire temperature sensor of Radiator

[ronenfe]

Does anyone know how to test this sensor?

[Broadcasttechniker]

You can only safely test it by letting it dangle in a pot of boiling water.

[ronenfe]

Ok. But what should I measure? What is the purpose of each wire?

[Broadcasttechniker]

You measure the contacts which of course will only close at the temperatures mentioned.
The middle one is common, which one of the ones on the is for high and highest temperature you will find out.
Use the continuity range of a multimeter.

[ronenfe]

Thanks allot

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I only get continuity between the 2 far pins. The center pin never connects to any of the other pins, so either my switch is bad or it has a different purpose?

[ronenfe]

I only get continuity between the 2 far pins. The center pin never connects to any of the other pins, so either my switch is bad or it has a different purpose?

It works. I had to wait a long time. Also the diagram I attached is wrong. It should be like this:
   

[Broadcasttechniker]

The picture you're showing now is another one.
The one on the left is common and the one on the right 82-92
The one in the middle will be 82-97.
It is not easy to reach 97 degrees in boiling water, especially if you live in the mountains.
You can think of a solution to get the temperature a little bit higher, for example with a hot air gun.
But please don't damage the harness.

[ronenfe]

I have a small leak from this sensor, even after I put a new gasket. Any Idea how to stop it?

[Broadcasttechniker]

The solid copper ring is absolutely useless.
Even a hollow one doesn't always work.
Eather you'll try one with a rubber lip, or, an i would prefer that, use teflon tape.
This works well. It's the same problem like with the seal für the oil pan screw https://www.twingotuningforum.de/thread-12765.html