I posted this once before, but not really good answers.
Old dodge van mid 70's, 318. Alternator had spacer that one bolt slipped
Long time ago I lost the spacer and used washers to align the pulleys
with the bolt alone.
Worked for a long time.
Now: LOUD squealing on startup, when engine warms up, squealing goes
away. Squealing ONLY occurs simultaneously with alternator gauge needle
bottoming out in charge position, alternating with normal position, in
which case squeal disappears-i.e. as long as needle swings back to
midrange position squeal disappears, only to reappear when bottoming to
charge position. Squeal and bottoming of needle go away completely when
motor warms up.
Checking the belt it is one of these kind that has teeth on inside
pulley side surface. Belt looks ok-not worn; appears undamaged, but is
somewhat loose about 3/4 to one inch deflection.
pulleys SEEM to be aligned correctly eyeball check only.
How do I differentiate between a squealing alternator versus a squealing
loose belt vs a squealing out of alignment pulleys? What is causing the
alternator gauge needle to bottom itermittently to full charge, swinging
back an forth between that and midline reading-is this a function of a
bad voltage regulator?
I cannot run this thing too long as my neighbors will complain about the
I wish to avoid replacing a $100 alternator if that is not the cause.
How do I differentially diagnose the cause of the problem. Anyone?