First off, I wanted to say I was recommended from a friend that this site has the best and most informative members as compared to many other full-size Chevy forums. I'm glad to be there. Thank you.

Second off, I have a 2006 Chevrolet Silverado Z71. It has recently started randomly dimming and flickering the headlights, instrument panels lights, interior dome lights and taillights. The voltage gauge typically reads at 14+v, but will occasionally down below the middle mark and into the 13v range. It seems to do these voltage switching at random time and intervals. I can be traveling down the roadway at around 60mph and the headlights and instrument panel lights are clearly dimming on and off. I do not have a stereo system installed, so no power from that could be disturbing my electrical phenomenon.

I would like to know which components to start with as I test through them. Is it a cable issue? Is there something wrong with a voltage regulator? Is the generator defective? (I had it tested at Advance Auto Parts and was informed that it was good, however the odd electrical phenomenon was not happening at the time of the test.

I'm sure I am leaving out some important information regarding my issue, so please ask me any questions you may have and I can quickly and easily answer them for you. I appreciate the help in advance y'all.

Thank you.

 

Sounds to me like the alternator/generator could be taking a turn for the worst. If it were me, I'd take it to a legit real shop that will load the alternator, or remove the alternator for testing that way. When they put the alternator inside their bench tester, it gives a better test than it does when they use their hand held device.

I'd check a few things first: load test the battery, make sure your battery cables are clean and tight, load test the alternator. If you have access to a tech2 scanner, I'd scan all the modules in the truck and look for signs of low voltage codes present in the modules. If you find those codes, that indicates further evidence that your alternator stopped charging and the battery ran low while the truck was running. It's possible you might even see a code for the alternator/generator too.

But if it were me, I'd lean towards a faulty generator.

 

I really appreciate the reply back. I meant to reply back earlier, but have been busy. I will look into your suggestions and report back. I have another issue to tend to with the truck now as well. The, what I believe to be the rear brakes, are sticking. It has been so cold in these parts that I haven't removed the rear wheels to check on that yet either.

 

I have a similar problem but only when I first start the truck. It will do it for about 15 min then go away. I have not tried to fix this problem yet but have researched it. There is a lot of information pointing to a common problem with a resistive connection within the alternator. I would first check all the connections especially the grounds first. My truck has 254k and a new alternator would not be a bad part to throw at it.