Voltage regulator??????

[nailr65]

I read an old post about lights flickering and a buzzing sound under the dash.  I have this problem and I am sure it is the voltage regulator.  I have replaced it three times with an aftermarket and what I thought was a decent one from NAPA.  I still have the same issue.  Can anyone school me on what specific brand or what ever, to solve this problem? 

Thanks Dave

[Brian]

Most likely not your voltage regulator causing the problem--it is just a symptom of the problem--especially since you replaced it and the problem is still there.  Usually that is a sign of the alternator charging really hard--like when there is a dead or open circuited battery.  I have jumped off one of these cars before that had an open circuited battery and the voltage regulator did exactly as you describe until I put a good battery in it. 

[nailr65]

Hi Brian thank you for the info.  I replaced the battery the same time as the voltage regulator.  I had a cheaper regulator in the car at first and it ran fine with no noises or flashing of lights.  The only thing with that regulator was the the Gen light in the dash stayed on.  At this point I searched for the corrected one but very hard to find.  I found a date coded aftermarket on Ebay and thought I was good.  Light went out ran good and no noise.  Just recently when I first start and run the car no noise.  After it warms up and I run it for a while then turn it off and start it back up that is when the noise begins.  Could the temp have something to do with it?

[Brian]

That sounds to me like one of the diodes in the alternator is going bad.  When one of them gets an intermittant open circuit in them, it will make the voltage regulator buzz like that as it comes in/out of contact.  A bad diode will also make the gen light come on and stay on.  Sounds to me like you have one that works sometime, and not others.  An alternator/starter shop can check your diode bridge in the alternator and tell you if something is wrong there.  They are pretty cheap and easy items to replace in the alternator. 

[nailr65]

I figured out that it is a temperature thing.  After running the car and getting it hot I shut it down.  When I start it back up I get these symptoms.  The other day it wasn't so hot out side so the car didn't get to it top running temp.  it didn't have the  symptoms.  So I guess my next question would be, can the workings in a voltage regulator be gapped?