Reviving this topic as mine has gone a tad stiff, so first off, thank you Craig for posting this.
For those with a 4/4, does your heater control knob just turn or do you have clicks? I did a few searches on TM and a few have posted that they do in fact have clicks/indents on the heater knob but it's not clear if that is a Plus 4 only thing or not.
See post
here. It seems that some cars including mine didn't have the detent ball fitted from new despite the quadrant providing for this hence no clicking positions. All trads in recent years use this same heater control system.
