[Shotimes] Electrical/Alternator Question...Ford, but not SHO ....3-pager

[George Fourchy]

OK....I'm going to try to finish this question properly before I send it this time. 
And, I apologize for it being a 3 (and a half) pager.  To those who have already
responded, thank you.  As I said last night, I had a slightly different question to
ask in addition to what you were able to make out from my incomplete paragraph at
the bottom.....

Here we go....!!  ;-)  Repeating the first part for clarity.


Hey, all..

Now that the list seems to be working again, I have a question.

Please read all the information before answering...thanks..  ;-)

This is on my '87 F-350 Crew Cab.  It has a 460 CID, with Holly carb....built a few
weeks before they went to EFI.  It has full gauges, with a voltmeter, and also a
battery light.  It got a new alternator 11 years ago.  I didn't change the output
connector then, despite the strong suggestion to do so.  That new alternator lasted
until a couple of weeks ago, when the connector finally overheated and melted.  I
got a new alternator, with a new connector, and changed them both, and used the
dielectric grease that came with the connector.  It now puts out much more voltage,
even when all the accessories are on, than the other one ever did.....that's why the
connector needed to be changed...it was corroded, and blocked some of the current, 
and got too hot, finally letting go after 11 years.

There are two plugs on this alternator.  Each one has three wires...one has three
small wires, various colors.  The other one, the one that burned, has three wires,
too.  Two of them are very big...obviously carrying the load, and they go (at least
one does) to the starter solenoid, where the battery connects, to charge it.  I
didn't follow the other one when I was replacing things, since I needed to get it
running.  The third wire on the plug with the two big ones is a very small wire,
white with blue stripe, I think.  I thought it went to the automatic choke, to
provide constant voltage to it so it will warm up and let the engine idle slow after
it warms up.  That wire is temporarily disconnected, since the original one shorted
out long ago to the engine block, and gave me an alternator light, even though I had
a charge on the voltmeter.

OK...here's the question....

I don't have a wiring diagram, so I can't trace the wires now.  The problem is that
when it is running, and I have a really good charge indicated on the voltmeter, the
battery light is still on.  I remember us talking about the battery lights in SHOs,
and how they turn off after current is flowing one way, rather than the other.  

...........new portion begins here.............

Just before the first alternator quit, and I replaced it without changing the plug,
the battery light was on, yet the voltmeter indicated a charge (like now)....at
least the voltmeter was awake....I don't remember if it was all the way up to a
proper level, but the battery never was run down.  I took the truck to Sears, to
have the alternator tested, and it took two different test machines to find that
there was something wrong with the sine wave from the alternator....the first
tester, a more simpler one, did not show a failure.  

Before this alternator was put on, before the plug finally melted, the light was
never on when the engine was running.  Voltages weren't as high as they are with the
present alternator, especially with all the loads running.....a/c, lights, blower
motor.  But the light wasn't on.  The third wire on the output plug, with the two
large wires, was not connected to anything....I think it used to go to the automatic
choke, but that wire shorted on the engine, and I just wrapped it up and let it stay
an open circuit, wrapped around a heater hose.  I haven't fooled with the other
connector, the one with the small wires.  (The engine takes a little longer to come
down to hot idle, but it does.)

So the question is, why is the battery light on, when there is a really good voltage
indicated on the voltmeter (with all loads applied, telling me that the now burned
plug was bad the whole 10 years)?  I haven't fooled with any other wires, other than
to just wrap the new small wire on the new big wire plug with tape, and it isn't
connected to anything.  If it only went to the automatic choke, does the charging
system care if that wire is not hooked to anything?  

Biggest question......If in fact I only have the light because the voltage is not
flowing correctly, as one of you said earlier, can I just go in and take the bulb
out?  Is all that I care about having a good charge indicated on the voltmeter?  Do
I need the light if I have a voltmeter with good voltage?

I just don't have any experience with electrical troubles, so I am not as familiar
with them as I am with suspension, brakes, and whatever.  Thanks for your help,
already received, and coming now.

George