Agree with you and am also a nerdy geek...
Normally, on complex systems (which seems to be everything these days) techs
and advice is to replace parts willy-nilly...or so it seems, but also say it
must have worked for them
Lucky they got the right culprit, but many times is miss
So from reading some of these posts...the OP's TV has an electrically initiated
fan clutch. Whereas in the old days, silicone fluid coupling with a thermo-bimetal
strip that was the sensor and switch
HOATs (hate any of the organic acid coolant), it is imperative to flush it BEFORE
the stated time on the labels
Organic ACID means the organic coating is the protection and the acid to etch
all metal surfaces in prep for the coating
Since not all of the organics nor acid is consumed during the initial coating...
they are highly reactive to O2 (air) in the system.
Back on the fan system.
There has to be one and most likely more than one temp sensor. The computer
will then turn on the clutch at some preset. If more than one sensor, then a
complex set of look up tables then sum to determine whether to turn on the fan
clutch
The AC also adds to that look up table for decisions
Just an educated guess if the fan clutch is controlled by the computer
If not, then whatever sensor(s) there are, will trip the switch to turn on
the fan clutch
The overall health of the cooling system must be in order, as a hot spot in
the wrong place can have the sensor trip the fan clutch
I'd start by using an IR heat gun to check temps all over the main radiator
and hoses/etc
Shoot the temp sensors too and their surrounding metal parts
Of course tough to IR the spots when it's only happening when moving...but the
mean average of all the parts should be indicative of their temps when moving
Good luck
