I removed the spare wheel and fiddled with the heater control valve which
had seized up in the 'hot' position. By squirting WD40 and wiggling it in
conjunction with the lever, I freed it up and it now works to a large
extent.

I would recommend people trying that first.

However I cannot get the full range of control, the valve will go all the
way 'hot' but not all the way 'cold'. Is there a simple adjustment I can
make with the lever to fix this? The lever stops about 1cm before reaching
the left hand edge of the slot.

1984 GL, 187k miles

Lionel Tun
ark@saqnet.co.uk