Re: Pulsing Alternator (Ithought it was just me)

["Tom Harais" <tjhemh@domain.elided>]

Russ:

My Scout did this same thing for a few months. This started after I used to
loose the headlights after applying the brakes hard, but then they'd come
back.

To make a very long story short, this later turned into my truck attempting
to start itself at various times, both when driving down the road and when
just sitting, key not even in the ignition, in the driveway.

THE CAUSE WAS THE BULKHEAD CONNECTOR! The heavy positive for the ammeter
had shorted to the heavy (wire gauge that is) ground inside the connector,
but the short was intermittent. When a little short occured, like fast
stops, it would take down the lights. When a very momentary short occured,
it would "tweak" the alternator and I had the "flashing" headlamps and
ammeter. When a big short occured, enough current flowed to engage the
starter (wherefrom the very large, always hot, + wire comes through into
the cab).

Hey. A "professional mechanic" (a local who everyone says is the smartest
repair guy around) diagnosed this as being a bad alternator and wanted to
charge me $150 to put in a rebuilt.) That's why I hate professionals so
often, they get in too much of a hurry to "fix" things and don't do a
proper diagnosis. He knew the alternator was "full fielding" but he didn't
know why. Rather than track it down, he just wanted to replace the
alternator and hope that was it. Of course, this type of "diagnosis by
elimination" saves the mechanic time and wastes the owner/operator's money.

If you want to test your bulkhead connectors, to out and start your Scout,
hood up. Turn the lights on and then wiggle the bulkhead connectors and
nearby wiring. If it misses, the lights flicker, the starter engages,
you've got a bad contact or a short developing in the connector. This was a
real weak spot in IH vehicles.

Wish I had know that back then instead of living with all the problems it
created for almost a year. It's real hard to explain to your freinds how
your truck can sit there and engage the starter while it's locked up in the
driveway.

Tom H.