1998 Chevy Suburban alternator is overcharging and battery

  • V8
  • 2WD
  • 115,000 MILES
I have a 1998 Suburban and this is a follow on from my earlier post.

The battery light begins to blink in a continuous pattern not random once the engine is off of idle. This is accompanied by pulsing in the electrical system. The lights, radio etc. Pulse along with the battery light.

When the car is idling the battery light goes off.

The alternator gauge shows 14 volts at idle and increases to 16 volts when the car is driven on the road.

The previous owners said they did not replace the alternator recently and the problem started about a year ago and is getting worse.

What conditions result in the alternator putting out more than 14 volts or so? Especially since it worked ok before the problem began. Is the alternator the problem and is there a voltage regulator or relay that would cause the constant non varying pulsing?

What item in the electrical system could cause a fluctuating voltage that pulses rhythmically.

When the battery light begins to pulsate the airbag light begins to flicker on and off but not in the same rhythm.

Any suggestions would be appreciated.
Do you
have the same problem?
Wednesday, January 13th, 2010 AT 8:42 PM

1 Reply

Ok the regulator is built into the alternator. So what I would do is test the battery and then the alternator. I would check with you local parts stores and find one that will do a free battery and charging system test. This will one check the batterys condition and then put the alternator through a series of tests and let you know if it is bad. My thought is that you will find the alternator to be bad. Let me know what you find.
Was this
Wednesday, January 13th, 2010 AT 9:20 PM

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