Battery or alternator ?
 

Starts quickly and voltmeter is at or above 14 volts.

It will stay at that voltage until I start turning things on and it drops to around 12 or less.

Turning off those things (lights, heated seats etc ) does NOT make it go back up. The voltage drops and stays low.

Turn it off and immediately restart and it is up over 14 volts again. Turn things on, and the same thing repeats without recovery.

It starts easy every time.

I'd have the alternator tested. Sounds like the regulator might be bad.

I don't wanna comment any more than thanking your post. Mick might come in here and mop the floor with my suggestions. :leaving:

It starts? F it and drive on!

Hold a screwdriver near center back of alternator with engine running and see if you can feel the magnetic field. If you can't "feel it" from at least an inch away you'll need a new car. If you can then have it tested. :leaving:

Only if they are dumb. Oh, so in other words, yes.

The first thing I would do is drive over to the local Auto Zone or similar on my way home from work today and have them test my battery. It takes about 2 minutes, and they usually do it for free, so why not eliminate something off the top. :shrug:

These voltages, are they from the voltmeter in the car, or a handheld one tested at the alternator? If it is the voltmeter in the car, I would see if the Auto Zone place will test your alternator, also usually free and only takes a few minutes. If they don't do that, and you have a multi-meter, you can test it yourself at home. It's more or less doing what you already did, but relying on your multi-meter rather than the meter in the dash. There are numerous YouTube videos giving an easy procedure to run the test.

How long has this been going on? If it has been a week or two, and your battery hasn't gone dead yet, I'd bet your alternator is good, but testing it is quick, easy, and also free.

FWIW: I suspect DJ is right and the problem is the voltage regulator.

It was the voltage regulator.

In the category of "no good deed goes unpunished" last weekend my buddy and I were helping jump a car and he hooked up the cables backwards. He grabbed them to swap the clamps and they were already fire hot. I'm sure that killed my alternator. It just took a few days to show up.

Stupid VW has a RED cable on the negative terminal.

Regulator prolly :yesnod:

I considered cracking it open and changing just the regulator. I mean with my awesome electrical skills, what could go wrong?

You'll have your serpentine belt rerouted through the casing is my guess.

You say that is if it is wrong. :island14:

Your timing is awesome!

Timing ??? I thought it was the alternator. :D

:rofl::rofl::rofl::rofl:

:lol:

L O N G time ago I went to Autozone for an alt. 108 amp factory rating, when I went for the dual spal fans, but the thing is a 17SI so the old style with two conductor plug on the regulator.....well the drive pulley had to be changed due to my having serp drive, I have had TWO replacements so far under lifetime warranty.......and this latest one I thought I had a bad bearing, no, it's a whine from it putting out heavy load, hear it from under the hood.....I dunno what to make of it, thinking of upgrading to a later model, but it's a PIA.....

:dance::confused5:

I'm sorry I couldn't hear what you were saying over the constant drone of your voice.

Well, I just threw 300 bucks out the window.

The truck was doing the exact same thing this morning after replacing the alternator last night.

It was Autozone and their tester that indicated the voltage regulator was not working. This morning, when it did it again, I thought maybe something in the truck is blowing out the VR. So I did more digging and came across this nugget of knowledge...

What I believe the Autozone diagnostic tester did, was evaluate the charging condition when the truck did not have the demand required to kick it in to the 14V charge condition, and read it as a VR failure.

The alternator has had two hours of time on it, and of course, NO RETURNS on installed parts. I now have a spare.:ulan:

You paid 300 for an alternator at Autozone?

:withstupid:

Wanna buy a bridge? :bigears: