At the end of yesterday's exciting episode I had discovered that the
alternator was putting out something like 18 volts or more, so this morning I
went to
the NAPA store and got a free replacement and installed it.
Before reattaching the alternator wiring I decided to recheck whether or not
the fuel pump would drop out when hooked up to the original (still suspect)
white power lead WITHOUT the alternator connected to the system--the fuel pump
started ticking when I turned on the igntion key and upon starting the engine
it continued to run for approximately five minutes. That told me
something--though exactly what I was not sure of.
I then wired the alternator in, went through the same process--this time with
an analog voltmeter attached to the battery posts. After the engine started
up the fuel pump continued to run normally for about 30-45 seconds, then
dropped out just about the time when the battery voltage went up to peak
voltage
(about 14.5 volts). That also told me something.
I bought a small 12 volt relay and using the (now not-so-suspect) original
white fuel pump power lead I wired the relay to make (close) the circuit so
that
it would energize when I turned on the ignition key, then ran a #12 wire from
the positive battery post, through the relay's circuit and to the positive
lead to the fuel pump. I turned on the key and the fuel pump started to click
away. I started the engine and the fuel pump continued to run merrily along.
I
went for a five-minute ride and the fuel pump operated perfectly.
It seems to me that there is something in the fuel pump's circuitry that does
not like receiving power from the fuse panel when the alternator is running
or producing peak power, something that is "cured" when the pump is powered
directly from the battery. Again I am thinking that the battery in some way
serves as a filter or buffer, perhaps levelling out some transcients, etc. that
are coming from the alternator.
I don't think I have solved the problem so much as come up with a
work-around. I'd feel a lot better if I understood the cause and will
appreciate any
suggestions others might provide.
Thanks everyone for their patience and input.
Best--Michael Oritt
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