Starter current

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Bidz
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Starter current

Post by Bidz »

Quick one - I hope!

Does anyone know what sort of current the start motor draws in firing up the engine?

Planning a rewire. Thanks in advance.
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bmcecosse
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Re: Starter current

Post by bmcecosse »

Several hundred on a cold start.....
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chesney
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Re: Starter current

Post by chesney »

Workshop manual
"Its lock torque is approximately 9.3 lb.ft. (1.3 kg.m) with 300 to 350 amps. and 7.5 to 8.0 volts"
While it does not list specifically what current is drawn, it seems reasonable to assume that they are around those figures.
Bidz
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Re: Starter current

Post by Bidz »

Thanks both. I'd assume that the current used to trigger the solenoid is much lower, any idea what this might be? My multimeter is limited to 10A so I'm afraid to measure anything I suspect to be quite powerful.
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bmcecosse
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Re: Starter current

Post by bmcecosse »

Very little - 5 amps inrush maybe ??
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chesney
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Re: Starter current

Post by chesney »

To trigger it? It's only joining two pieces of metal together via mere electromagnet. I replaced mine with 10 amp wiring on my '61 4 door, which seemed more than 'amp'le (pardon the pun). If this is in aid of straight rewiring, just follow the original colour wiring codes available online, red on white for solenoid.
Bidz
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Re: Starter current

Post by Bidz »

Interesting. I've replaced my keyswitch with a push button start (Chesney you've seen this) on the red-on-white, but several "Heavy duty 25amp" push-to-make switches which claim to be for ignition circuits have failed.

I am now considering a relay triggered by a button!
“The car has become an article of dress without which we feel uncertain, unclad, and incomplete in the urban compound.” ― Marshall McLuhan
chesney
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Re: Starter current

Post by chesney »

While I assume that, your background in consideration, you are using quality parts, I would suggest it pays to do so. On my '61, I used two relays from a 'high street supplier' (one I'm guilty of having worked for) that went pop very quickly, despite their relatively nominal role. Switched to relays from 'RS Components' (who I highly recommend) and no problems since.
We only have to look at the condensors 'we' buy nowadays to see electrical components are not all they are cracked up to be.
I cannot see that the solenoid will use any more than 10 amps (the wiring itself as standard is 10 amp max iirc), certainly not 25 amps. Perhaps there is a short in the r/white line?
Unusual for switches to fail (in numbers) as they are relatively mechanical, however I'm not very familiar with the switches you describe.
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