Morris Minor Owners Club

have you checked that its charging,you've fitted new battery,(they need running to get full charge) but still need jumping to start.Jump start it,point it at a wall switch headlights on,watch the refection of lights on wall with it ticking over,rev it the lights should now show an increase in brightness. if not its not charging . I see you have a multimeter .Test the battery before starting then when running(reved up) Post your results.

New ,cheap batteries can also be duff.

Jennifer whilst your diagnosis is sound ,don't think his moggy is an auto.

And don't forget that, with a partially discharged battery, in the absence of a jump start you can turn the engine over on the starting handle to start it, which won't pull on the battery like the starter motor does. Why this handy feature was dropped from cars I'll never know. Good for turning the engine over slowly for setting points and checking valve clearances as well! Obviously, make sure the car in out of gear when using the handle. Don't use your thumb in grasping the handle in case the engine kicks back.