battery light

[csford]

my o3 doesn't have a volt meter on it but a light instead.I noctice that light comes on some times.It comes on for 15 -20 min than goes out.Today I drove for 30 min that light was on for 15 min then I stopped and got out for a minute than it was out.Any ideas? ( never seem to have a volt meter handy)

[DryHeatDude03]

Alternator going?

[lifewitlooie]

could be battery terminals , batteries or alternator. I guess alternator or terminals. chekem out

[csford]

the post seem tight and not dirty. bad ground?

[deviusdragger]

well if it was the alternator your batteries would be dead. Look around at your wiring and fuses.

[csford]

today on my drive to work it was on and off on the way home it was on for 10 min out of 30 could it be the voltage reg? bumps don't seem to do any thing so I don't think it's a lose wire but I'm not a mech

[csford]

Just put in a voltmeter the other day ad have drivin it and have drivin it a couple times the light comes on but the meter stay around 14.Does that light chesk some thing else (amps)? No problems starting the light has been coming on for 3+ months.Any ideas?
thanks

[bismic]

I would load test the batteries if you haven't already.

[redracer62]

turn the ignition on, but dont start it. hold down the odometer button on the cluster. then start the motor(keep holding down the button). then let go once the motor is running. if done right you will be able to see a lot of crazy but useless info an the volts is in there you just have to find it by pushing the button. it took me a couple try's my first time i did it. that will tell you the alterator output while driving

[kmack]

I'm having a similar issue on an '04 Excursion (6.0L). Battery light comes on periodically, but never stays on.

Had the batteries checked at the parts store: they said they were ok.
Had the Alternator checked at the parts store: they said it was ok.

Voltage check on both batteries w/o engine running = 12.49V
Voltage check both batteries w/ engine running at idle (no accs) = 13.5 (pass) & 13.3 (driver)
Voltage check both batteries w/ engine running at idle (w accs) = 12.61 (P) & 12.48 (Dr)
Voltage check both batteries w/ engine running at about 15oo rpms (w/ accs) = 11.84 (P) & 11.80 (dr)
Voltage check both batteries w/ engine running at about 2k rpms (w/ accs) = 13.11 (P) & 12.88 (dr)

During all voltage checks, battery light was off.

Voltage check both batteries w/ engine running at about 2k rpms (w/ accs) & light on = 11.8 (P) & 11.73 (dr)

I'm assuming that my alternator is starting to die. Am I correct with this? Does this all look & sound right?