Hello, anyone knows the thread size of the second hole on the Douvrin thermostat housing, next to the temperature warning light sensor? I plan to install a temperature gauge and use this hole for the sender. I seem to recall it’s M18x1.5 but I’m not sure. Can’t find definitive size in the parts microfilms.

I found the answer on Lacitroencx forum, so someone might find it useful. Thermostat housing with 14x125 warning light slot appears at OPR 3281 (November 1, 1985). On the thermostat housing until OPR 3280 with warning light probe in 16x150, the second location of probe is actually in 18x150, this probe is mounted if "air conditioning, country very hot"