Those voltage are pretty normal for a car with a 12v system, perhaps the 9v
is a tad low. Shouldn't cause you any problems though, if it is cranking
but not sparking something is wrong with your ignition. The 9v could be a
weakish battery, or could be bad connection on the ground side as well as
the hot side (which you have bypassed). Connect a voltmeter between the hot
battery post and the solenoid post and measure the voltage while cranking.
Do the same from the ground battery post and the starter body. Ideally you
should only get about 0.25v each side, which is the voltage being dropped in
good connections and the cables. Anything over 1v is worth cleaning all the
heavy current connections - don't forget the engine/gearbox ground strap.
Any other voltage loss is within the battery, which can be measured by
putting a voltmeter across the battery posts while cranking.
PaulH.
----- Original Message -----
From: Glenn <g_wakefield@yahoo.com>
To: <mgb-v8@autox.team.net>
Sent: Thursday, June 28, 2001 11:56 PM
Subject: Another electrical question
> What is everyone out there getting for voltages on the
> + side of the coil. I'm getting 12V with the key "on"
> but down to about 9 V with the car cranking. It is
> cranking at a pretty good / usual speed. I'm running
> a stock Buick starter (rebuilt), MSD Coil (although
> I've also put in another coil, and get the same
> voltage). Remember, the car was running just fine
> until it died on Tuesday. I've tried running a jumper
> wire from the battery straight to the plus side of the
> coil, but still only got about 9.5V while cranking.
>
> I'm wondering if this might be what is causing the
> Pertronix EI not to function.
>
> Bad battery?
///
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