Starter shorting/cooking wires

[leeandoona]

So. My minor which has sat idle for many many many months wouldn’t start or even turn. It’s a 58 and has a pull starter. When pulling the starter knob the dash lights dim. I checked the power to the starter motor and sure enough there was no power reaching it. I bridged the connection on the switch but this did nothing and did a volt meter test and no power was jumping from one side to the other unless bridged. I tested the starter independently and discovered it too was not working so removed it, bench tested and sure enough it was dead.
During all this I noted the wires were getting very hot when attempting to start/power the starter.
So I checked and cleaned all the earths, including the gearbox earth strap. Bought a new starter which I bench tested and confirmed was operating. Fitted the starter, pulled the starter knob and the starter span once and then after an audiable bang, it stopped working and returned to hot wires and dimming cabin lihjts.
Checked fuses, checked earths again. All lights operate as expected so appears to be electrically okay on that side of things. Removed new starter to discover it too is now dead. So it’s cooking starter motors. I’m assuming this is a short?
I’ve bought a new starter switch/solenoid (I know it’s not really a solenoid).
Anyone had this happen? I don’t really want to fit another starter and Jill that too!

[oliver90owner]

First thing - can you confirm that the engine actually turns?

Further response after that.

[StillGotMy1stCar]

Is the engine seized overloading the stalled starter motor. Can you turn the engine with the starting handle, fan or rocking in gear.

Regards John

[leeandoona]

Engine turns freely. Yes. Not seized and I e turned it over using the starting handle.

[oliver90owner]

Was the replacement starter motor a secondhand purchase or bought from a reputable source of refurbished starter motors.?

If the latter, I would think they should replace the unit. I cannot understand how the starter should fail so quickly. The loud bang would indicate something is shorting inside the starter motor. I’m assuming, here, that you did not engage the power for too long.

[leeandoona]

Brand new from reputable minor specialist. No, it was literally one pull on the starter and a brief spin over of the engine, then bang and failure.

Wires from starter and to battery very hot. Can’t see any obvious signs of bad earth, all earth points nice and
Clean and when checked for continuity they show appear normal.

I’m assuming there is a short somewhere?