I have a 95 wagon with 1.9L engine and don't know if the fan is working. The gauge on the dash doesn't go further than center, but the engine and the coolant seem to get very hot.
Had quite some pressure in the upper radiator hose
Thermostat is new, OTC monitor tested fan and relais good
The small unit on the pic is the sender for the gauge
Is the bottom one the engine coolant temperature sensor, and is it responsible for starting the fan and what are the specs of the two?

I appreciate any help and suggestions

 

Just in case somebody is interested -found some data about sender and sensor

 

1996 Ford Explorer. Small coolant leak only when the truck is off or cold.
Doesnt leak when it is at 200-220 degrees. Not much coolant but any coolant
leak would be ideal of course. I can find where is coming from, but it looks
where the lower hose goes into radiator. But wouldnt it leak all he
time?Any ideas please? thanks

 

I dont know if you can trust the resistancies of the sender I posted earlier
I couldn't find any with 500 ohms cold and 17 ohms hot, but I put a Standard Motor Product TS 300 in that measured at about 2.5 Kohms cold and it seams to work, although the gauge worked fine when i probed it with resistors
Very strange

 

Little crack in the tube where the hose is mounted under the hose, or hose or clamp on crooked or clamp loose - when its hot everything expands and might seal itself
-But this are only ideas-