No, it all works off the ECT sensor. How many miles on this van?
I think your head gaskets might be going, have they ever been done before? Pull number 4 spark plug out [left front of eng] and inspect the electrode ground tip for being a shade of green [assuming you have clean coolant in it now]
Ok it is normal for it to run a tad hotter when not running the a/c. Does the fan ever kick in with the a/c OFF?
The fans run all the time due to the a/c requires air flow over condenser, thus the engine runs a little cooler..
With the a/c off, the pcm lets it get a little hotter before engaging hi fan.. This should happen by 3/4 of the way in normal zone of temp gauge. Will really need a computer scan tool to look at the eng temp and when fan is energized to be for sure on this one.
Here is fan strategy from shop manual
The fan control system consists of two two-speed engine cooling fan motors.
The engine cooling fan motors are wired to operate only when the ignition switch is in the RUN position, thereby preventing engine cooling fan motor operation after the ignition switch is turned to the OFF position.
The cooling fan system is controlled during vehicle operation by the constant control relay module (CCRM) and powertrain control module (PCM) (12A650) which will energize the engine cooling fan motors under the following conditions:
Engine cooling fan motors are turned on if:
Cooling fan will run at high speed if:
did you test the radiator like I suggested, just because you sent it out does not mean its OK. Does coolant ever boil out of the degas bottle?