Identify this part

Oh yeah, sorry about the pic quality too, damn near impossible to get the camera in close enough to get a good shot.

Yeah, that's the water temp thermo-sensor. The signal goes from there to the ECU.

FYI - the small brass sensor above and toward the passenger side of the engine sends the temp info to the guage cluster and the sensor on top of the thermostat housing on the front of the engine is the one that turns the fan on when the temp reaches hot enough, so I'm not sure why you're having a fan issue due to the pictured sensor above.

Engine Coolant Temp Sensor

It's the sensor that talks to the ECU and then the ECU decides when to turn on the fan.
The 1.8 cars are completely different than you 1.6 car.(Tim) If the sensor is giving wrong data to the ecu, than the ecu will not turn the fan on....

BTW, good job trouble shooting. I'd send you a beer, but It would be warm. I'll just drink one for you instead

Yeah, there is nothing on the front thermostat, and from what I could see and manage to squeeze my hand behind the engine, just the one sensor. any others on the 1.8 that you might be able to think off that I should check?

The only other thing to check would be the wiring. There could be a bad ground, a broken wire, or a short....I'm having the same problem with my 95 project car....I'm just too damn busy to get out and do all the work, that and a little lazy.