electrical and ignition terminal to clean up this wiring?

[josh72ooh2]

Out of curiosity after you drive your car for a while what does the battery voltage read 15 minutes later?

It is just under 12v when the car is warm, and the voltage light comes on.  But it isn't always on at warm idle.  It will go on at a traffic light, and then maybe come on again a few lights later.  So it is inconsistent. 

I got home and the light was on (car still running), i tested the voltage at the battery at just under 12V, then I pulled the car into the driveway, the light was off (car still running), the battery tested around 13+Volts. The voltage regulator is a new solid state one.  However, I am running one of those 85Amp alternators off ebay.  It is 5 years old.  Supposedly has an internal regulator.  yet I have always had to connect my old voltage regulator to it via that one DF wire.  I can't remember why but I think but if it wasn't connected, either the 'L' light would come on or the voltage would drop a lot. 

[JayMac]

Okay, you could have a few problems:

 

Battery no good

Alternator no good.

 

If you have a meter check to see at fast idle @1500 what your voltage is. If you don't have at least 13 and the is a bit low I would have the alt checked out. If you do I would have the battery checked out. Should be @12.7 volts charged. Advance auto will check both for free if you bring them in. Both are easy checks and should get you on the right path.

[josh72ooh2]

I actually had both checked out while I was trying to find the culprit of the parasitic draw. O'Reiliy checked the 1.5yr old battery and it is fine. I took the alternator to the shop I got it from and they bench tested it and it was ok. I think they put new brushes in at that time too.

I have a feeling the alternator is not working consistently all the time though. Something, in addition to a nice low idle(due to fuel injection), is causing it to fail at low RPM.

Sent from my iPhone using Tapatalk

[JayMac]

When you say warm. is that with the engine running? If the engine is off and has been run for any length the battery should have more than 12 volts. Fully charged it should be at 12.6 to 12.7. If the voltage reg is internal it could be that also. Unless you are drawing gobs of amps for some sound system. Then maybe you can mess with you pulley combo. Also, age of the parts means nothing...although we like to think so. When they decide to go they never check to see when you purchased them.  If you have someone to help you run on everything at idel and check your volts. One of the issues we found is that an alt can be good but does not put out the current it is rated for and that could be your issue also.

[josh72ooh2]

Yes, warm and engine running.  sometimes just under 12V.  sometimes 13+.

Car off, 12+ volts. 

I disconnected my alarm and sound system a week ago.  The alarm was the culprit of the current draw.  The sound system does have a subwoofer but it isn't anything crazy.  

But nothing has solved the occasional dip in volts.  My guess is that the internal voltage regulator in the alternator is goofy.

I can disconnect the battery with the car running and it will still run (indicating that the alternator is OK).  Although i haven't tried that when the 'L' light is on.

[JayMac]

I would tend to agree on the regulator based on what you have.

[AustrianVespaGuy]

Here's what mine looks like.  Just bought this at Lowe's or something.  Has a rubber gasket to seal out the water, but easy to undo the latch to access it in case of a jump etc.  Also goes nicely near where the batter was originally, and protects everything from short circuiting wrenches!