Jim Grant's Tech Tips
Lumina, Alternators for Breakfast
Q: Our ‘91 Chevy Lumina is eating alternators; we have replaced
it 4 times. This time it went out in 3 weeks. How can I find a solution
for this apparently fairly common problem? ....Philip
are some items you want to keep an eye out for when dealing with a reoccurring
alternator failure problem. *Inspect the auto belt tensioner. A binding
tensioner assembly will cause premature bearing failure. *Check the mounting
brackets. The mounts that support the alternator cannot be bent or damaged.
Misalignment of the mounts will put stress on the alternator case that
can result in failure. *Inspect wiring and connectors. Look closely at
the wires and connectors at the alternator. It is not uncommon in older
vehicles (even happens in newer) for the terminals in the connector to
loosen up and lose contact. The act of unplugging and plugging the connector
will be enough to allow for contact for a short time. This also goes for
the wiring itself. The wires can break inside the insulator (plastic covering)
and not be seen. Moving the wire around briefly causes the connection
to be made, only to be lost later. * Wiring to and battery condition.
An alternator needs a good path for electricity to flow. If there is corrosion
in the wiring the alternator will be overworked and overheat resulting
in failure. A bad battery can kill an alternator too. The battery may
be good enough to start the engine but bad enough to cause the alternator
to overwork (overheat) and fail * The alternator. Are you getting a really
good deal on the replacement alternator? Too good of a deal is not a deal
at all when it comes to what is needed to correctly rebuild an alternator.
Bolting on cheap rebuilt parts can cost much more than you realize.