charging system light coming on and off

[menaztricks]

The charging system light has been coming and off for the last few days. The starter, alternator, and battery are all a year or less old. Had them checked out and everything is good. Today while the driving, the charging system light came on, then the stereo stopped working, first no sound, then it just turned off. Shortly after, all the other lights on the dash started turning on, one by one. Any ideas what the problem could be?

[gerend]

Hi there menaztricks,

The first thing I'd check would be the "big 3" wires: From the alternator to the battery (+), From the Battery (-) to chassis, and from engine block to chassis. Since your alternator & battery are relatively new, it is very possible that the problem could be as simple as some corrosion around the terminals (clean with a stiff wire brush), or possibly the cables are bad. More than a few times, I've replaced the "Battery (-) to chassis" cable, and fixed an apparent alternator problem. In addition, sometimes there are fusible links inside the black "split-loom" cable wrapping (usually on the (+) wires, so check that too. It is very easy, and cheap, to start there. If it doesn't fix the problem, you're only out a couple of bucks and a few minutes of time.

Also, is your battery sealed-cell? If not, check that the cells have enough juice in them! Often, if I'm not sure, I'll just throw a $30 Wal-Mart battery in...If it fixes it, great...if not, oh well! It's not like I just dropped $200 on an Optima battery!

Just be sure to use the proper procedure when connecting/disconnecting the battery: for examples, be sure to disable airbags, obtain stereo "theft-lock" codes, and so on. Usually, you should disconnect the (-) battery cable first...but read the directions to be sure!

If adding/replacing wires to the Battery (+) side, be sure to add appropriate fusing as close to the battery as possible: this is a critical safety issue often overlooked; in extreme instances omitting this step can actually cause the battery to explode! So don't forget your fusing!!!

It could be that some problem (e.g. "big 3", bad alternator, etc) causes other components to go out: I've had a new battery get killed by a bad alternator, and these 2 also overstressed the starter (low voltage means less torque and longer key-turns). Had to replace all 3 of these at the same time, and still had problems: turns out, there was a $5.00 relay in between the battery & alternator that was intermittent, wouldn't always allow the battery to charge...but when it did, the alternator was charging a severely drained battery. That $5.00 part cost me several hundred. And hours of head-banging. (NOTE: this was in a 1985 Toyota Celica, 22R-E engine). But just be aware that this can happen.

Hope it helps,
~Gerend