Another suggestion:
Bad brushes or having brushes move not well for good contact.
Cheers,
Hans
----- Original Message -----
From: "Paul Hunt" <paul.hunt1@blueyonder.co.uk>
To: <Cyc10@aol.com>; <mgs@autox.team.net>
Sent: Tuesday, July 13, 2004 4:04 PM
Subject: Re: Starter problem when hot
> You need to do some voltage measurements to determine whether it is a
> connection or a motor problem. Whilst a low battery voltage will cause
the
> motor to turn slowly, a mechanical problem that causes the motor to turn
> more slowly with the same battery will cause it to take more current and
> hence lower the battery voltage. A bad connection that reduces the
current
> through the motor will also cause it to turn more slowly, but the battery
> will have less load on it hence its terminal voltage will be higher.
>
> Take a reference voltage measurement at the battery posts (not the
> connectors) with the engine cold and the starter cranking the engine
> normally, then take another reading when the motor is hot and the problem
is
> evident i.e. turning the engine slowly or not at all.
>
> If the second reading is *lower* the problem is probably a mechanical
> problem with the motor or engine not turning fast enough i.e. mechanical
> stiffness but could also be a battery problem.
>
> If the voltage is *higher* it indicates a connection problem and the full
> voltage is not getting to the motor. Taking voltage measurements at the
> battery posts, connectors, battery cable stud on the solenoid and a good
> body ground, solenoid stud and the starter body, and the motor connection
> from the solenoid - if you can get to it - and the starter body will help
> break down where a bad connection is. As long as the solenoid *is*
> operating and the motor *is* trying to turn, it is nothing to do with the
> starter relay.
>
> PaulH.
>
> ----- Original Message -----
> From: <Cyc10@aol.com>
> To: <mgs@autox.team.net>
> Sent: Tuesday, July 13, 2004 4:27 AM
> Subject: Starter problem when hot
>
>
> > My 1970 MGB has a problem when the car is hot. When I try and start the
> car
> > after it has been running the starter turns very slowly and it sounds
like
> the
> > battery has lost power. Some times it will not even turn the engine
over.
> > The battery was checked and it is in good condition.
> >
> > When the car sits a while and cools down the starter works fine and the
> car
> > starts right up.
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