[Tigers] Electrical short during start attempt

[Steven L. Finberg]

Hi Graham

You don't have  a short circuit.   You have an open circuit in the starter motor connection.  
This is a wide braid connection from the engine block to the frame and back to the battery negative.
When you try to start several hundred amps need to flow.  Since the strap is broken (open) the current
tries to find an alternative ground thru your small black wires over heating them :-( . 
Trace and fix the starter ground then see if the small grounds need replacement.


Steve F
67 Alpine
________________________________________
From: Tigers [tigers-bounces at autox.team.net] on behalf of Graham Harlowe via Tigers [tigers at autox.team.net]
Sent: Friday, July 20, 2018 4:57 PM
To: 'Tiger's Den'
Subject: [Tigers] Electrical short during start attempt

After gassing up this morning I went to restart the car.  When I turned the
key, I got VERY slow and reluctant turnover (not enough to catch) and heavy
draw on the voltmeter.  Turned the key again for another attempt I got the
same thing and noticed a wisp of smoke from under the hood.  When I popped
the hood, I noticed a burned/melted section of the wire harness in the
vicinity of the alternator.  Dang.  Once home (tow truck), it appears a
couple of ground wires had borne the burden of a short.  One of the scorched
ground wires runs down the loom along with the temp sending unit wire and
(on my car) attaches to a mount for the coil on the intake manifold.  The
other fried ground wire attaches to the base of the ballast resistor.  I
have a one-wire GM alternator, not the stock generator.

I have the a wiring schematic, but a diagram of the harness and what these
two wires (or perhaps one wire with two connections?) are supposed to serve
as the ground for would be helpful.  I could splice in some new black wires,
but that seems pointless without understanding what caused the short in the
first place.  Any ideas where/how to look?

Thanks much,

Graham Harlowe
B382001466






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