I have a 1968 with charging problems. the alternator was discharging, so I had a mechanic look at it. he adjusted the external voltage regulator and said that he did the best he could do with it. After that, it was constantly overcharging and he said he couldn't do anymore with it, so I replaced the voltage regulator with a new OEM Delco regulator. Now the voltage gauge needle constantly quivers or shakes. So I had the alternator rebuilt thinking the brushes may be getting worn, but this didn't help. Does the regulator need adjust to stop this quivering needle?

 

I assume you mean the ammeter not voltage gauge, have you tried using a temporary external gauge to determine whether the problem is the gauge or the charging system?

 

yes you are right, it is the amp gauge, sorry for the confusion. I checked the output of the alternator after it was rebuilt and it is putting out the correct volt and amps.

 

Amp gauges usually jump around at idle but smooth out after 1000-1500 rpm. Does yours smooth out?

 

no, it will keep moving even when driving on the highway.

 

I had this exact same issue. The original and more expensive aftermarket replacement VR are completely mechanical. They have two relays on the inside and the one constantly opens and closes very, very quickly to regulate the voltage. It's actually quite normal. The amount of fluctuation varies with the load on the alt. If you adjust the VR almost all the way down it will almost stop, but it won't be charging. If you crank it up, it will swing wildly and boil your battery. I know this because I played around with it and then set it to around 13.5VDC, I didn't boil the battery though.

If you want to stop the fluctuating, dare I say it, get the cheaper not-made-in-usa version of the VR which is all solid state. The solid state unit doesn't have any mechanical parts in it to wear out or need adjusting. It also doesn't use the relays that are constantly opening and closing causing the fluctuation. You call also tell the physical weight of the two, the solid state unit is very light compared to the OEM style.

Here is an example of the solid state version. This is the one that I am using and it solved the flickering. The price alone is worth a try. Also you can swap the covers from the old unit to the new to keep the look and feel of the OEM.

http://www.oreillyauto.com/site/c/de...tage+regulator

Now, you will ALWAYS see the ammeter jump whenever the load changes such as the turn signal, headlights, brake lights, etc. But you should just see one flicker when the load is applied and then one when it's removed. When you turn on the turn signals, you will see the gauge flicker with each cycle of the turn signal. This is completely normal and to be expected.