Saturn Battery Light... unfortunately not as simple

I drive a 1996 Saturn SL2. About 2 months after purchasing the car,
the battery light came on. As most would think, I took this to be a
problem with the charging system. Using a voltmeter, I checked the
voltage on the battery. 12 when off, around 13.5 when running warm.
Seemed ok. Saw that the voltage dropped a small amount once the
battery light came on (or vice versa I guess). So I proceeded to
replace everything. I replaced the alternator, then the battery, then
the drive belt, and finally the battery cables. The issue still
occurs, and it's driving me crazy. Any ideas? And more specifically,
since I don't have the owner's manual, can anyone tell me EXACTLY what
it says in the manual about that light? Any help would be greatly
appreciated. Thanks

 

A good battery, once properly charged should hold 12.6 volts, not 12.
If the alternator is charging properly, mine is closer to 14 volts,
not 13.5. 13.5 volts will work, but not optimum.

I am curious if you replaced the battery and alternator at the exact
same time. I have seen many times that a bad battery burn out a new
good alternator in just a few hours or days.

I know it is a PITA, but maybe you need to have your alternator bench
tested in a machine to check the output to see if it can handle the
load.

Another thing to check: The charging wire that connects the alternator
to the battery wire on the starter. Maybe it has a bad connection or
corroded fuse link. That wire had a recall on it when my car was just
a year old. The old wire didn't have a fuse link, the new one did. But
they go bad as well, even intermittent.

James

 

'96 should be obdii so have diagnostics run on it. See what the ECM
perceives the battery voltage to be. Could just be a broken sense wire or a
corroding contact on one of the connectors.
Few things are easy...