Ian,
I learnt an interesting trick from an RAC man one day. If you hear the click of the solenoid, but the starter doesn't turn, then turn the key and whack the starter with a hammer at the same time (via a long drift if your starter is as inaccessible as mine and it probably needs two of you). If the starter then turns it's likely the starter is on its last legs.
I had a random failure of the starter on my Sportster. But it worked when I whacked it. I changed the starter and have had no problem since. I didn't measure any voltages though so can't comment on the numbers you get.
And now I've just read your original post on this and maybe it sounds a bit more complex than a simple starter problem. But it's probably worth trying to eliminate it if you can.
|