Slow cranking is unlikely to be a problem with the ignition switch because
the switch operates a relay which operates the solenoid and it is that which
carries the current.
Connect a voltmeter from the hot terminal of the battery (not the clamp, the
actual terminal post) to the hot terminal of the starter if you can get to
it or the hot terminal of the solenoid if you can't. Crank the engine and
take a voltage reading.
Now do the same from the ground terminal post of the battery and the body of
the starter.
If you get more than about 0.25v for either reading you have less than ideal
connections somewhere along the line (so to speak), if you are getting more
than a volt you have a significantly bad connection.
Use the same technique to measure the volt-drops along the hot and ground
circuits, but the usual culprits are the battery cable to battery box
connection and both ends of the engine to body ground strap. It could be
anything, though, and quite possibly more than one.
This is all assuming you have a decent voltage at the battery posts while
cranking.
PaulH.
http://freespace.virgin.net/paul.hunt1/
-----Original Message-----
From: Rick Huber <rickhuber@home.com>
To: dstieber@paccar.com <dstieber@paccar.com>
Cc: mgs@autox.team.net <mgs@autox.team.net>
Date: 23 June 1999 23:48
Subject: Re: the big drain.
>Drew,
>
>Thanks for the tip. I'm thinking it's more the ignition switch now,
>since the problem continues with the fuse out, and the starter and
>solenoid are brand new. Now after a full charge of the battery the
>starter still turns slowly. I'm unequipped to test the amps, but maybe
>I'll borrow an ammeter.
>
>Cheers,
>
>Rick
>'75 V8 B slowly electrically dying
>'65 B undergoing lengthy restoration
>
>" (Drew Stieber)" wrote:
>>
>> Spontaneous draining battery: Good job of finding the trunk light
staying
>> on that could definately cause a problem. But now that you are leaving
the
>> bottom fuse out has the problem gone completely away?
>>
>> If it has gone away you have other circuits that are draining available
>> power from the battery. As an example newer cars have lights that come
on
>> automatically, and they turn off while the car is cranking. If they dont
>> turn off there isnt enough juice to crank the engine.
>>
>> What other circuits are on that fuse? Aftermarket seat warmers, radios,
>> fans, etc...any one of which could be draining the battery. And than
there
>> is ths lucas gremlin. You may have a small short somewhere in one of
those
>> circuits caused by a frayed wire or something.
>>
>> Or it could be you have a problem with your starter or starter soleniod,
or
>> maybe even your ignition switch. Are you sure the battery is drained? or
>> is it just acting like it is? A dirty contact in the ignition switch, or
>> starter solenoid will make the starter turn slowly (not enough juice
>> getting ot the starter). You can check the starting amps going to the
>> starter with a shunt and an ammeter.
>>
>> Good luck,
>>
>> Drew
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