Truck won't go, electrical

["sherman" <shermano@prodigy.net>]

Hi Linda:  I'm not going to cover Alternator, Battery, or Regulator.  They
probably have all been replaced by now. Right?!
   Next... Have your mechanic check them to make sure they are working
properly.  You must have gotten at least a 10 day warrantee on them.
   Moving right along... Check the obvious first.  Like you said, something
might be trickle-draining the battery.  Do not assume the engine rebuilders
did not pinch a wire.  It may have just taken 33,000 miles to wear through
the plastic coating.  To check that, first make sure there are no dome
lights, dash lights, radio, or anything using battery power.  Then remove
the positive battery post.  If you have a voltmeter, test for voltage
between the battery cable and the positive post.  If you don't have a
voltmeter, just hold the positive cable very close to the post and touch it
gently a few times looking for spark and listening for spark. Even the
slightest spark is not good.  Remember that trailer brake actuator is hot
all the time and takes a little battery power, but nothing that would drain
a battery even in a week of sitting unused in the driveway. So if you have a
separate wire for the trailer brakes, remove it temporarily.
(Now some people will tell you that you can get a shock from 12 volts.  This
is not true.  You can get a shock if there is an inductor in the circuit,
but there shouldn't be one in this circuit.  Now don't go proving me wrong
by putting your tongue across the battery posts.)
  Ok, so we were looking for spark.  If you have a little one, then figure
out what is causing it.  If you have a big spark, you will soon have to find
out what is causing it or you will have a fire or a fuse will burn out. GMs
have a fusible link on the positive post.  That is a piece of wire on the
positive battery post about a foot long that goes to a connector and on into
the wiring harness.  If there is a loose connection at that connector, about
one foot from the battery, it will cause poor charging and intermittent
starting and low battery indicator. This fusible link is designed to "open",
or act like a blown fuse when too much current is drawn from the battery. If
this happens, you will have to replace it, (the link).
  You may have to replace a few more items before you find the source of
your problems.  Do you want to sell your truck?  Does it have a full-sized
bed?  I love electrical problems.  They are hard to figure out sometimes,
but can usually be fixed by making a better connection, or cutting off a
wire and replacing it with a new one.
  About 20 years ago I graduated to computer wires and don't get much chance
to pull out the ol' voltmeter.
 So keep us up to date on your problems.  If you have a trustworthy
mechanic, use him.  Otherwise try to do the stuff your self.  There are some
places that will give free advice and free testing of electrical devices, if
you bring the part in, like Discount Auto, or Pep Boys.
  I'm sure there are about 100 knowledgeable truck mechanics on Ridecamp.
So let's share our experiences and see what cured other people's electrical
problems.
 Sherman and Kandu in Fl
http://pages.prodigy.net/shermano/kandu/home.htm