Temperature readings don't match...

[KenP]

While driving to work this morning in my '96 S500, I noticed the temp gauge on the dash to be abnormally high... still below the red zone... but well above "normal" ... especially since the temp outside were pretty cool. I was getting gauge indications of more than 110 degrees C.
Normally, I can hear the aux fans coming on around 100 degrees C or so... but, heard nothing this morning despite the high indicated temp.
So, I punched up the coolant temperature on the pushbutton control (climate control unit) and it was only about 192 degrees... right where I would expect it.
So, my temp gauge on the dash didn't match the pushbutton control...
Just went out at lunchtime and everything looks normal and the two units agree.. and temps stayed below 100 C on the gauge... with 192-194 degrees indicated on the pushbutton unit.
Are there two temp sending units? I'm wondering if one is dying and giving me erroneous high temp indications...
KenP