Sounds like you are talking about the GREEN 3-pole temp sensor?!
The two different readings are for 2 different functions, the 105C is for turning the aux fan ON. The 115C reading is for turning the A/C off if the engine gets that hot!
If you want to get the aux fan on at 100C then you need a RED switch part # 006-545-42-24 to replace that old green one.
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