10.5v when cranking is normal-ish. If it cranks slow at that voltage the
implication is that there are one or more bad connections in the cranking
circuit, it would be useful to know what the battery post voltage is when it
cranks at normal speed (disconnect the coil to prevent it starting). I say
'normal-ish' because that is the sort of voltage mine show when cranking at
normal speed, but with bad connections causing slow cranking because of the
lower current I would expect the battery voltage to be a little *higher* than
normal. You can detect where the bad connections are by connecting a
voltmeter between the hot post of the battery and the battery cable stud on
the solenoid (ideally the connection from the solenoid into the motor if you
can get at it) and measuring the voltage while cranking, then from the ground
battery post and the body of the starter. In a good system you will see only
about 0.2v lost in each 'leg', if you are seeing closer to 1v in total it will
be worth measuring the voltage drop across each connection (i.e. battery post
to connector, connector to cable, cable to solenoid, cable to body, and the
engine/gearbox ground strap). I have seen as much as 3v being lost in the
cranking circuit.
At a *fast* idle with minimal electrical load you should also be seeing much
closer to 14.5v at the alternator, battery and fusebox.
PaulH.
----- Original Message -----
From: Cyc10@aol.com
To: paul.hunt1@blueyonder.co.uk ; mgs@autox.team.net
Sent: Monday, August 02, 2004 5:20 AM
Subject: Re: Starter problem when hot
At idle voltage was around 13.5 V at all these points. Took car out for a
long ride and came back and checked voltage. Turned car off and readings
around 12.5 (cannot remember exact amount). Tried to start car and voltage
measured around 10.5 volts at all of the points and starter was sluggish. Let
car cool down and all values returned to normal and it started right up.
Check out the new British Cars Forum:
http://www.team.net/the-local/tiki-view_forum.php?forumId=8
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