Where is the Tempetature Sending unit on my 98 4.6

 

I believe it is near cyl#5 under the intake.

 

Perfect. It sounds like it's in the black hole of these 4.6 engines. My gauge always indicates the exact same temperature after the warm up. I think it stops at a certain point no matter how hot it gets. Heat of the day or cold of the morning, A/C running or not I always get the same reading after warm up. That just can't be. Any way to test the temp sender. Maybe boiling water and electric meter? Any advise

 

Ford set up the gauges to read normal with a wide range. You will not notice any heat soak showing in the gauge. Seems people want gauges to feel like they know, but don't really care as long as the gauge is center. It is most likely reading as designed. If it get overheated it should show on the gauge. The truck will disable cylinders if it gets really hot, so there is an indicater. lol Someone will chime in here, but I believe it is a CHT and not a water temp unit.

Maybe someone knows the tep-resistance chart of the sender and you could ohm it

 

That is correct. This is done so if it runs out of coolant, it will see the head getting hot and the gauge will still rise and send the computer into limp mode and disable every other cylinder to cool it down.