i have also looked into this (but had to give up as the wrecked car which i was trying to get it from was being sold)
there is an extra (small) wiring plug at the back of the climate control unit
(which is not there on the normal one - but iirc the plug for it to connect to in the loom is in the models that dont have the option, its just taped to the side)
theres also the above-mentioned sensor on the dash
(didnt get to look into how this might be able connect up)
and the only other thing i could find was a (weird) bit of piping which goes from the back of the unit
(comes out of the rear of the cavity that has a small grill at the front left side)
and runs past the ecu and connects to the plastic housing where the lower air vents are (drivers side),
and the part where it connects is slightly different shape in the model which had it to mine which didn't...
(i think its the in-cabin air temp sensor, and the one on the dash is for outside (?)
as for changes between the models/series/phases,
the later versions were different to the early versions in the following ways:
(this relates to the japanese ones only)
- body colour ivory/marble white [KJ7] replaced with super white [531]
- body colour only available in black [KH3] or the above super white (no more grey [TJ1] or red [AJ4])
- umbrella holder removed (blank panel rather than vent from RB model)
- headrests changed to solid-style (from hollow-style)
- interior fabric trim changed to the same as the SSS model (no longer special just for GTI-R)
- badge on front grill changed to "Nissan" (from the Prince "P")
- steering wheel changed to all black with Nissan logo debossed (instead of red GTI-R logo button)
- windscreen changed to monotone (no upper blue section)
- roof lining changed to vinyl from twill (except for those that had the sunroof option)
- main instrument cluster logos changed to hidden unless lit (and ANTI-LOCK logo became ABS)
shalom
[earlymodelsarethebest!]
Hey- anyone know if i can swap over a climate control heater/unit from a phase 2 R into my phase 1 (which only has air con but no Climate control?) Surely if it's just controlled by the computer that's in the heater control unit it can't be that difficult?