headlights flickering

[ChewyJ]

At approx 1500-1900 rpm and under a slight load, my headlights start flickering intermittantly (1999 k3500 p/u).  A/C and radio are off.  I am just concerned that my headlights may just go out completely in the middle of the night....

 

Anyone have this type of problem go to the failure point, or is it simply a normal function of the truck due to the alternator output at this rpm range?

 

Thanks for any help....

 

I should also mention that the voltage meter does not fluxuate when the lights start doing their thing.

[TxDoc]

There was some discussion of this in the past. It seemed like it was rather common with the GM trucks. But...

 

Mine started doing it, and did it for about 2 months. Then, the alternator failed. It would flicker-at idle, when and without the brakes applied, at speed, accelerating, etc.  When it failed, it did so abruptly.  I never had any battery discharging problems prior to it failing.  I drove to the gym, it was okay. Left and on the way home, voltage dropped and when I got home the battery was so drained, the engine was coughing and sputtering and the tranny was shifting differently.

 

See what others say.

[TahoeMan]

Might check the long, expensive, positive side battery cable running to the starter for corrosion on both ends.  I think you're seeing symptoms similar to what happened to me...