Pulsating lights

[89K5guy]

When my K5 idles in drive the lights pulsate not flicker on and off.My factory volt meter for what it is worth reads 13-14 volts which i know is good.As i drive the pulsating stops and may not do it again until i start the vehicle again and put it in drive. Any ideas folks?

 

[neverendingproject]

prolly your idle is set at your alternator cutoff, so the lights flicker with the alternator coming on and turning off.

 

[jtexfisher]

I had the same problem...had yuck in the battery cables. Tried cleaning, fixing..no go. Finally just replaced BOTH of 'em and all is well now. So nice to open the door at night and no more pulsing dome light! As the above post said, increase of idle would fix it, but in my case the real culprit was the high resistance in the charging circuit.

 

[hunterguy86]

I had that in my old dodge truck. It went from that to no start at all. I changed the voltage regulator, alternator, starter, and switch in the dash. Still no start. It turned out that a wire behind the volt meter came loose and was grounding out. It was a pain in the ass to find. After fixin that all was good.

I've also seen lights that were dim at idle but got brighter w/ more engine speed. Always a sign that the alt was goin bad in the times ive seen it.

It could also be a bad ground.