Battery Light

cheeks

Founding Member
Nov 30, 1999
262
0
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Hey guys, I have an 89LX and the battery light is on and I can't figure it out??...(I have a 3G and Red Optima battery)...the voltages taken from the battery are as follows... 13.12 when the car is not running, and 14.42 when the car is at idle...any ideas?
 
Possible voltage regulator failure in progress. The Battery light is hot on one side anytime the ignition switch is in the Run position. The voltage regulator provides the ground that turns the light on. If it grounds the light while the engine is running, it is either because the voltage is low or the voltage regulator is going bad. All 87-95 Mustangs have a voltage regulator buit into the alternator.