Testing Starter Motor

[John P]

Hi,

I've been getting everything together to finally fit a starter to my Ulsteroid.

I have what looks like a reasonably good starter motor but I haven't been able to check if it works OK as I don't have a serviceable battery and don't really want to buy one whilst I can't actually drive the car.

Just out of interest I laid it on the bench and tried connecting it to an old style battery charger hoping it would at least spin a little but there was no sign of life at all although the charger did show a current was flowing.

Is it just that there's nowhere near enough current available to spin the motor or do I have a problem?   I'd have thought that if it was just a lack of adequate current then the charger fuse would have blown.

Anyway, do I wait until I have a battery or start looking at the motor now?   If I do need to overhaul it then apart from cleaning the commutator and checking the brushes what electrical checks should I perform?

Any advice would be much appreciated.

John.

[Peter Sweeney]

You could use a 12 volt battery and jump leads on the bench. Should at least tell you its working, should not do any damage. My special has been running 12v for 40 years without a problem with the 6v starter.

[Charles Levien]

You could use a 12 volt battery and jump leads on the bench.  Should at least tell you its working, should not do any damage. My special has been running 12v for 40 years without a problem with the 6v starter.

make it secure before you juice it up as it will kick back.

[Zetomagneto]

Hold it in the vice, a lot of torque reaction particularly on 12v.
Stay safe, stay out of A&E

[Barry Townsend]

Hi John
I had exactly the same problem with my RN starter, no amount of urging would get it to spin even on the bench. I carefully dismantled it and found the bushes on the ends at the armature were seized. A simple clean and lube solved the problem. I took the opportunity to clean the brushes etc whilst it was apart. Woke like a charm now.

[Robert Leigh]

A typical starter motor even on no load will draw an initial current of 3-400 amps. There is no way a standard battery charger will give enough current to get a starter going.
Robert Leigh

[John P]

Thanks for all the advice.

I'm a bit reluctant to take the battery off the modern as it leads to all sorts of issues with the electric windows, entertainment system etc.

I think I'll just install it as is and if there's a problem when I eventually get a battery I'll have to deal with it then.

I was just hoping to eliminate any potential problem as when we can eventually drive our cars again I'll be very reluctant to start stripping it down.

John.

[Reckless Rat]

Whatever you do, don't take the battery off the modern even if it is flat. Many cars these days will need to have the on-board computer and stuff rebooted if you do.( RTFI )