Something I am completely confused by
While running AC the driver side left and middle left vent are noticeably cooler (haven't tempt it but drastically 12 maybe 15 degrees cooler) than the passenger. driver side feels icy passenger side almost as though Ac doesn't exist.

Middle right and right vents are significantly warmer almost as though the AC wasn't on?
Rear vents are what they have always been - just there for fun seemingly not doing much but do still feel cooler than front rights.

Any idea on the cause or what to attempt to do to fix. I'm really lost on this one

99 xjr

 

I'd make sure both blowers for the HVAC system are working, if not you can get strange flows through the system.

That's a bit of a guess though, others will know more.

 

Interesting, I will look into it (all vents have what seems normal pressure [they blow about the same strength] just completely different temps)

 

Fortunately , the trim door motors can be run back and forth as you put a 9 volt battery on the climate control module connector ( not as buried as the motor connectors ) and with a good ear you can hear the target motor run , this proves motor good and just motor position sensor bad ( so it goes wonkers ), there is a work around at this point not needing to dig out and replace motor

You have a cabin climate control panel cabin face bite test that will identify specifically the motor by fault code numbers found in the X308 TSB list

This is a Youtube video someone made of almost the exact same Denso system on the X300 ( minus the center vent trim potentiometer negated on the X308 )

See page 110 0f the doc linked below

T703 BOOK