440 Si Won't Crank, Bump starts but no motor cranking Options

[geoffa]

Hi all, Hopefully someone can help please. My 440 Si 1.8 had it's battery flattened and afterwards would not crank. Tried several good batteries and plus a 50A charger also connected - so not that. There is a loud click and the courtesy light dims but no cranking. It bump starts no problem (so immobiliser must be OK ?). The voltage at the battery drops to about 9V which is odd as I would expect not much drop to operate the solenoid and much lower if the motor was actually getting connected (like nearly a dead short if it is jammed). I've known starters to jam on the flywheel, rotate but not engage, but not do nothing.
Is it a pre-engaged type ? so maybe it is just not engaging and so not contacting ?
Battery cables and posts etc checked cleaned and tight (but not yet on the starter) - I read somewhere about a white main fuse - is that in the feed to the motor ? not seen a fuse there before.

Any other ideas please ?

[grendel1960]

the starters do stick on these, mine did it several times, with just the symptoms you describe, get a long bar and give the starter a good thump, if that works its the starter sticking, if not you will probably need to take the starter motor off and check it out off the car (come to think of it if it is sticking it will need to come off for cleaning / lubrication)
Grendel

[geoffa]

Thanks grendal1960. I did not give it a bang on the basis that it had to come off anyway. The heatshield is bug**r so it just got levered off (will deal with that later) then it is quite easy to get out. The 4 permanent magnets had detached from the casing and jammed the rotor (so maybe a hefty bang is NOT a good idea.) Everything else looks good so I will attempt to repair - only problem is working/finding out where the magnets should go.

[geoffa]

RESULT - to anyone following this thread the repaired motor works. I took a guess that the magnets had not moved far and fortunately I had marked one so I knew where to put that then the opposing one is the same and the either side are reversed (4 pole motor). Thoroughly cleaned the magnets and inside the housing. Rapid Araldite did the trick. When it had half set I added some more between the magnets to provide a good fillet along each edge. And it goes the correct way so my guess was correct. Spent some time pondering why the solenoid would not pull in !!! Finally worked it out - it has two coils - one in series with the motor (until the main contactor makes) without the motor connected then not enough power to pull it in douuuugh.
Thorough clean up - leave it overnight for the Araldite to really harden and then back on the car tomorrow.
I would say giving it a bang is NOT a good idea - it could easily crack off a magnet - maybe on the main cast housing but definitely NOT on the motor body,