Folks,
All this talk of wire wiggling and terminal cleaning reminded me of a
simple diagnostic method. Voltage drop test. You can use a volt meter in
parallel to a circuit to see if voltage would rather go through the meter
than through the intended circuit. In very non-tech terms... If you
provide an alternate path to a circuit, and the current would rather go
that way than through the circuit, then there is a problem in the circuit.
With a meter, you can measure the "preference".
Specifically a starter circuit has essentially 3 circuits. The switch
circuit: put the voltmeter between the hot terminal of the battery (not
ground) and the small terminal on the solenoid, attempt to start. Meter
should read .5 (1/2) volt or less. The battery circuit (cable): put the
voltmeter on the hot battery terminal and the other end where the battery
cable connects to the solenoid, or the starter. Whilst cranking the meter
should be .2 (2/10) volts or less. Ground circuit: connect meter on starter
housing and to ground side of battery, whilst cranking meter should be .2
(2/10)volts or less. If your meter readings are higher in any of these
tests, then you suspect the connections or the cables or switches (if any)
in the circuit path.
It is conceivable that if more than one of the circuits is very near the
limit that combined the effect would be the "intermittent" problem you
describe. And with a marginal battery, the condition is exacerbated. This
got a bit longer than intended, hope it is clear and helpful. Clean those
terminals.
Peter C
Peter C.
MGC-GT , 100-4, '31 MM8 Cammy, Innocenti S(spoken for) ((now gone)),
'52 Champ, '60 L-R 109 SW, 3 '64-73 L-R 88's
nosimport@mailbag.com
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