[Vwdiesel] 89 Jetta D phantom voltage PROGRESS

[Doyt W. Echelberger]

Hello Bryan and the others that were interested in my "phantom voltage" post.

Since all evidence pointed at least to the alternator as the failure unit, 
I did the easiest thing and swapped in a new regulator with its new brushes 
and clean contacts.

The alternator now runs WITHOUT the very high pitched (but not loud) note 
that vaguely  sounded like metal on metal.

When I switch on the ignition but do not start the car, red the battery 
light comes on and the yellow "glow plug" light comes on.

The red light battery light goes off1 when the car is running.

I measured the output voltage at 14.3 volts immediately upon starting, and 
at idle.

The numbers look good.

I will test this new factor for a few weeks and see if I get into any more 
situations where the car won't start and needs to be jumped after sitting.

I also had a chat with a fellow that earns his living overhauling 
alternators and starters in a private shop. He said that my alternator (and 
alternators in general) are not set up to bring the car battery up to its 
maximum voltage, but only to maintain whatever charge the battery has by 
supplying alternator current to handle the load of light, fans, A/C and 
accessories when the car is running. He said you have to use a charger to 
bring the battery up to its maximum charge, and then have a working 
alternator to keep it that way.

OK, I listened to him and told you what he said. The guy has a building the 
size of my house, full of shelves of alternators and starters  and charging 
system parts, and a work bench with tools to tear them apart and put them 
together and test them under load. And he has been doing it for about 25 
years, working on all kinds of brands and vehicles, from bull dozers and 18 
wheelers down to passenger cars and motorcycles. (That sure tops my 
background by about a million percent.)

So, there you have it. Maybe some of you have comments. I think it has been 
a very interesting thread.

Doyt


 >>>>>>>>>>>>>>>>
At 10:10 AM 5/31/2011, you wrote:
>SWAP the brushes first from one of your spares.  The will cost you 0$ and 
>could be the issue.
>
>
>
>Bryan Belman, Pt. Pleasant, NJ
>04 Jetta Wagon TDI PD, 100hp, 5sp -- running :<)
>92 Jetta 1.6 Eco-Turbo Diesel, 5sp -- running :<)
>82 Diesel Westy 1.9NA -- running :<)
>70 Type 1 stock Elm Green Beetle -- Under Restoration :-)
>
>
>
>From: Doyt W. Echelberger <doyt at buckeye-express.com>
>To: vwdiesel at audifans.com
>Sent: Sun, May 29, 2011 11:19:36 AM
>Subject: [Vwdiesel] 89 Jetta D phantom voltage RESPONSES
>
>That was a HUGE amount of help, guys. I appreciate the detail and the 
>suggested tests. It will take me a few days to try the suggested tests. 
>But as you say, the fingers all point to the alternator. I have a few 
>spare ones from earlier Jettas that have gone to the bone yard, and if 
>necessary, I can buy a rebuild.
>
>James, thanks for the details on the blue wire and the diode tests and how 
>the alternator should hit 13.8 right away. That is 99 percent convincing 
>that the solution is to R&R the alternator, and I can get busy making that 
>happen.
>
>I'm leaving the Jetta at home until it is healthy again, and driving the 
>Benz out of town for Memorial Weekend activities. Thanks again for being 
>there with the virtual roadside help.
>
>Doyt
>
>
>
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