Overheating in dash board. Not actually overheating

Hey all. Was wondering if anyone could shed any light on my 1986 1.8 8V Passat's temperature sensors.

I'm wondering which one is responsible for the reading I see on the dash?
Here is a few pics




Thanks for any help my golf friends :')

Don't know specifically which is which but rule of thumb (yes I don't do Passants as they should of been spelt with a i )  LOL

the Water temp Gauge sending unit is usually tied to the
Front side (grille) or in your case the right hand side of the engine water outlet flange.  If the Picture I am looking at if the rear of the engine against the firewall isn't in a water outlet flange then it is either an oil pressure switch or a oil temp sender.

The oil pressure or temp switch are usually
 a green/black wire on the Golfs.

Yellow/red is usually the Water temp Gauge in the dash.

Thanks Brian, well you see my red and yellow wire is the back of the head?. The sensor there is tapped into a water way. So maybe that is it if the follow the same colour scheme as the golfs

I would.