Battery? Alternator light???

XxSlowpokexX

XxSlowpokexX

Registered User
Ok...So my dummy light has been going on and off for a few days....Not flickering..But it wont be on for awhile.....Then it will...Then noo...

So I had both the battery and alternator checked out while in car with one of those testers and all came out good. The light wasnt on at the time however.

So is that an amp or a volt dummy light..Also besides battery and alternator can that be anything else? all wires ae tight
 
Damon,

Last Alt I had that failed, did exactly as you describe. Light would go on, by the time I got to work or home it would be off and when I checked it, it was OK. Did this for about a month. So then one day going to work it stayed on about 5 miles from work, yep it tested bad then. Drove home with it on too. Made it home put on the spare alternator and all was good.

I have not looked at the wiring diagram for the SC, but if it is like other vehicles I believe the light is just measuring voltage. When the alternator is charging there is sufficient voltage to turn off the light, when it is not there is a voltage differential (0 out of the alternator) and light comes on.
 
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Charlie is right about the light. It time for a rebuild.
The Alternator Warning Indicator is connected across the terminals of a 500 ohm or 420 ohm (Electronic Cluster only) resistor at the Instrument Cluster. For the 3.8L without the supercharger and 5.0L EFI systems, current passes through the warning lamp when the Ignition Switch is in RUN, and there is no voltage at terminal S of the Regulator. When voltage at terminal S rises above a preset value, the Regulator switching circuits stop the flow of current into terminal I of the Regulator and the lamp turns off.

In vehicles with supercharged engines, the Alternator Warning Indicator lights up with the key in the RUN position and when the A terminal voltage is excessively high or absent, the alternator output terminal voltage is absent, or the internal diode trio voltage is absent. Both systems will illuminate the warning lamp with the key in RUN and the engine not running, indicating that the regulator is being powered up but the alternator is not yet charging
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When my alternator died it made a "singing" kind of noise that I couldn't diagnose until the car just stopped running.
 
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