323i where is the dash water temp gauge sender?

[cartem]

This is for a 1986 323i.
This dash gauge is barely moving off the bottom most position when the top of the radiator temperature is 200 degrees F.
So, I figure that either the sender is bad or the gauge itself is.

Seeings how the gauge is more "protected" from heat, etc. than the sender - that probably the sender is bad.

Problems is, even tho the parts sellers show 3 different ~ ~ "thermo" "sensors" or "switches" only one has connections that look like they fit what I think might be the sending unit for the gauge.

The one sensor that looks like it matches the parts sellers pictures is in the bottom of the radiator & I don't think that that is the one that drives the dash analog gauge.

Does anyone know for sure where exactly that sending unit is?

Thanks