Page 4 of 6

Re: Starter motor fault check list

PostPosted: Sun Apr 15, 2018 10:00 am
by jimj
No, the earth in the boot was the first thing I checked. I suspect those wise people who probably haven`t commented shrugged in despair and asked themselves; "why doesn`t the silly so and so (paraphrase!) just take off the starter motor and bench test it?"
Having given one last go with a jump lead from the battery negative to the motor casing with no effect, I`ve done just that. It took no time and the motor is completely dead though it`s only about 2 years old. Not only that but the teeth are chewed up yet the ring gear looks fine, thank goodness.
I`m looking at replacement prices and they seem to vary by 100%.
Jim

Re: Starter motor fault check list

PostPosted: Sun Apr 15, 2018 10:12 am
by john.p.clegg
Timing....no not ignition timing...just threw out four starter motors..

John :wink:

Re: Starter motor fault check list

PostPosted: Sun Apr 15, 2018 1:16 pm
by MarkDa
Anyway you should now be confident that the supply and earth are good!
I'd be tempted to get an exchange starter, with a bit of luck it will be based on Lucas originals and they are thoroughly checked unlike a cheap new one.
There are plenty of specialists, so probably one near you or the usual suspects will oblige.

Re: Starter motor fault check list

PostPosted: Sun Apr 15, 2018 3:29 pm
by Elanman99
jimj wrote:No, the earth in the boot was the first thing I checked. I suspect those wise people who probably haven`t commented shrugged in despair and asked themselves; "why doesn`t the silly so and so (paraphrase!) just take off the starter motor and bench test it?"
Having given one last go with a jump lead from the battery negative to the motor casing with no effect, I`ve done just that. It took no time and the motor is completely dead though it`s only about 2 years old. Not only that but the teeth are chewed up yet the ring gear looks fine, thank goodness.
I`m looking at replacement prices and they seem to vary by 100%.
Jim


Jim, you say the motor is completely dead. I could interpret that as being either open circuit (burnt out) or short circuit (failed insulation or trapped wire). From your previous statements your motor must be shorted (because its dragging the voltage down). What seems strange though is, if its a dead short and the solenoid is operated, one helluva current is drawn from the battery and I would expect even the thick cables would be getting warm.

It sounds as if you have taken off the motor, even though it needs repairing/replacing because of the pinion teeth it would be interesting to 'bench test' . It can only establish whether the motor runs but it only a limited test because the motor is doing no work.

Your negative jump lead test has eliminated a bad connection on the ground side, but the same test on the positive side, (jump lead battery positive to starter motor terminal) would have been worth doing to eliminate all the positive side of the circuit.

I am still curious where the 11 volts is hiding :?

Ian

Re: Starter motor fault check list

PostPosted: Sun Apr 15, 2018 5:27 pm
by Donels
Just an obvious question but I can?t see the answer in the Q & A so far. Have you checked that the battery is ok?

Re: Starter motor fault check list

PostPosted: Sun Apr 15, 2018 5:45 pm
by MarkDa
First post

Re: Starter motor fault check list

PostPosted: Sun Apr 15, 2018 9:44 pm
by Donels
Just because it?s fully charged doesn?t mean it?s fully functional. If the lights are dimming on engaging the starter often means that the starter is not supplying full voltage. Before doing anything else connect some jump leads from another vehicle. If the starter turns ok then it?s the battery if you get the same symptoms then you?ve eliminated the battery.

Re: Starter motor fault check list

PostPosted: Tue Apr 17, 2018 1:19 pm
by jimj
Just a footnote and a thankyou for the intelligent replies.
Autolec in Buxton have rebuilt the starter motor, it was shorting out inside. ?60 and a 24 hour turnaround. I`ve just fitted it and it`s all working fine.
Marvellous,
Jim

Re: Starter motor fault check list

PostPosted: Tue Apr 17, 2018 3:51 pm
by MarkDa
That's good to hear.
These simple old designs are eminently repairable and I expect he gave you a warranty!

Re: Starter motor fault check list

PostPosted: Sat Jan 05, 2019 1:03 pm
by Geoffers71
Sorry I have to resurrect this thread, but I have a similar problem and I need help ( an increasingly common situation these days :lol: ). My starter was becoming increasingly sluggish, but now it's completely dead. I've followed this thread and done all the checks recommended as far as I can tell ( although I admit to not being the most elecktricky savvy person around). Before I remove the starter and bench test here's what I've done so far.
Checked the bendix and it's free to rotate
Checked all the earths a remade most
Almost new battery recharged overnight
Checked the battery voltage which shows 12.85 V ( this is a bit lower than it was when first charged and after I'd been doing my tests)
This does not change much when when solenoid operated
12.85V also shown at solenoid live in and at out when connection made across terminals
12.85 V shown at starter motor live input when solenoid operated
Earths at starter motor cleaned and remade. Earths test ok

I'm not looking forward to removing the motor as it's increasingly difficult to get good access for me these days :roll: , so if there's anything else to check first. I can't see any advantage in running a battery supply directly to the motor as I have full battery voltage there anyway.

Re: Starter motor fault check list

PostPosted: Sat Jan 05, 2019 1:18 pm
by Craven
NO voltage drop suggests an open circuit, probably brush contact inside the starter itself.

Re: Starter motor fault check list

PostPosted: Mon Jan 07, 2019 12:44 pm
by Geoffers71
Thanks Craven for your suggestion. I've removed the motor and it is indeed totally beyond redemption I reckon.
Commutator is badly worn and brushes poor, in fact one had a broken wire so no wonder it didn't work. I've taken the plunge and bought a high- torque one from SJ so that should solve any future issues.

Re: Starter motor fault check list

PostPosted: Mon Jan 07, 2019 2:17 pm
by Craven
Could be a wise move as the replacements, non-original Lucas, starters on offer are of questionable quality.

Re: Starter motor fault check list

PostPosted: Mon Jan 07, 2019 2:29 pm
by ericbushby
Geoffers,
Definitely a good decision. When I fitted a modern pre-engaged starter, I was so pleased with it that I gave the Lucas motor away in good working order. I will not be fitting one of those again.
Eric in Burnley
1967 S3SE Type 45

Re: Starter motor fault check list

PostPosted: Fri Jan 11, 2019 4:31 pm
by Geoffers71
Well now I'm REALLY depressed :( After a great deal of difficulty and struggle lying on my back on a cold garage floor I've fitted a new high- torque motor and it's not working :evil: :evil: There's just the click of the original separate solenoid as though the starter is jammed. There's no facility on the motor to turn the bendix like the old Lucas one and as the car is up at the front on axle stands I can't try the rocking in gear trick. I've given up at the moment as I'm cold and ache all over, but before I reluctantly start all over again by removing the motor is there anything I can do to check and confirm where the problem lies?
I'll feel more stupid than usual if it turns out I've fitted or wired it up wrongly although I can't think of where I got it wrong. Is it possible that the bendix is not meshed properly with flywheel gear teeth, although the body is tight against the bell housing? Any help gratefully received.