i think something in my charging system is going south. and wanted to see if anyone has any suggestions?

a little back ground. i have a new red to optima. what appears to be a new voltage regulator. and an old alternator.

the alt light comes on with key on and then goes of when the engine is started. so this is normal.....

i have a digital volt meter that used to read about 13.7 volts. with lights on or off. it didnt matter.

but last night when i when out to a desolate road to adjust my headlights, i noticed it was reading 12.6 volts with lights on, and 13.2 with lights of.....

same thing today 13.2 lights off. this is not normal.

so my question, is it my alternator or voltage regulator?

on the early generator vw's, you could push the brushes against the commutator to clean them up and give the brushes a new profile. i have also put a strip of sandpaper on the eraser end of a pencil and brightened up the commutator.

but im not sure if this can be done on my 1.8L. it looks like alot of work to get at the alternator. and im not even sure if it has access holes to the brushes.
i know i should probly start by wire brushing all the connections but i dont think thats the problem. this has developed quickly.

the fan belt is tight.

any thoughts?

I noticed a fast switching between 12.5 and 13.4 when my VR failed. It was fast enough that my digital meter wouldn't pick it up on the display, but the true RMS bar graph did. (fluke meter). I put a new solid state one in and haven't had any problems..yet. But then again it's hard for it to fail if you cant drive your car

thanks jeff, where did you get a solid state one?

do the voltage regulators slowly stop working? i would think that they work or they dont.

Think I just bought one at Autozone or one of those El Crapo places to "test" . I say "test" cause it's been in there ever since. It was something like 30 bucks. I know the krusty one will flame me, but it was a nice weekend then and I wanted to drive the car.

is this digital volt meter mounted in the cab?

or are you testing the battery with a volt meter at the batter it self?

if you have a volt meter wired inside the cab and wire thru the fuse panel you really can't use that as a final diagnostic tool. you would have to back it up with testing at the battery with a volt ohm meter.

corroded connections will give you a degraded reading. check all grounds and the positive connections at the battery and then check the connections from the battery to the fuse panel. you will need to get very familiar with the wiring diagram that is source from many places [haynes manual, pelican parts forum, and search on this site] there are many connections between battery and the fuse panel [at the relay board is two] .

the volt meter is mounted in the dash. im gonna test the system with my multi-meter and clean all the connections. i just wanted a short cut. but i guess im going to have to get down and dirty.