Morris Minor Owners Club

is the rear heated window connected to the + side or - ? has it wasnt connected and i can't find it in the wiring diagram,thanks

A minor never came with a heated window, so you won't find it in the wire diagram. Its been added by a previous owner.

Which terminal the feed comes from will of course depend on what earth the car is running.

It is most likely that an alternator and negative earth conversion has been done (dyno would have a very hard time with a heated screen) so the screen would connect to the car body and be fed from a +ve switched feed.

If it needs to be re-wired make sure the cables are up to it, and it would be wise to put a relay in the feed so that it can only be live when the ignition is on. Something like that could flatten a battery in a very short time if left on.

Do not attempt to wire it directly from the switched feed (white wires at fuse box) the ignition switch won't handle that sort of current for very long. It needs to be wired pretty much direct from the battery via a switch (with suggestion of a high current relay which can be driven off the switched feed so it can't be left on).

now that explains why i couldnt find it, its still has postive earth with dymno and their has been a switch stuck on to the dash with a light that shows if switch is on,but now that you mention that it wont cope on dymno ,i think shant bother connecting it up just yet