The 1984.5 cars are the second to last of the mohicans, 240T-wise. The last were the 1985 cars, but those were only made for about 1/3 of a year and are slightly changed 1984.5 cars.
Differences:
- 1985 uses the later 240 fuse block configuration with the door chime wired directly to the ignition switch, instead of being fused as it was on the older cars.
- 1985 has rear fog lamps.
- 1985 saw deletion of the H/C and F/E markings from the temp/fuel gauges.
- OD light changed to a "5" on the 1985 cluster; OD OFF light changed to the up arrow.
- Turbo light deleted from the final 1985 turbo cars - essentially they just got GL model clusters.
- Overdrive wiring is the 1985-86 setup with the red OD relay and bullet connectors at the tranny tunnel on M46 cars and the 1985-93 setup with white relay on most Aw71 turbos. Some of the early 1985 cars did somehow wind up with the orange relay and older harness.
- Door chime is quieter, instead of the deafening loud version used on late 1983 and all 1984 cars.
- More color choices, redwood metallic reappeared, topaz blue metallic was introduced, black metallic was replaced by dark gray metallic.
- Leather feels softer and has a shiny finish to it, instead of the satin finish with a tougher-feeling hide used on the older cars.
- Parking brake console changed from early style without seat heater cutouts to 1986 style, but with blanks installed, sometime in September-October 1984.
- M46 received a different release fork with the clip-in bearing.
- Driver's seat heater received a cutout switch on the dash for 1985. Previously, it was controlled by the thermostat inside the seat cushion.
Otherwise, the cars are pretty much identical. A 1984.5 B21FT engine is the same engine as the one used in the 1985 car, right down to the part number. I've done most of the updates on my 245Ti, so it has pretty much become a very early 1985 245Ti, spec-wise. I don't have the dog dish flywheel by choice - prefer the flat one, I also am using the 1979-80 overdrive wiring. My 1984-85 CPR was funky, so I'm running a 1981-83 "079" CPR instead.