Zoltan..
the ground side of any cirucit is just as important as the power supply
side.

equally important.
12 volts to any device won't do a bit of good if the device's ground path is
broken, weak, or has high resistance.
the last time I did exactly what you are doing ..
it was lack of ground for the pump.  I ended up running a new ground wire
and then it worked fine.

You might look around for some manuals on basic electrical circuits used in
cars..
I see various manuals .
like Haynes has a good OBD-II one ..
and I recently invested in their Welding manual..
and when I see a book on 'Basic Electronics' .I buy  that ......figure I'll
learn something there ..
you could learn more about basic DC circuits perhaps.
Then just think how powerful you're feel, knowing you can outsmart fickle
electrons most of the time !

I bet you figured out the ground side thing after sending your post as well.

aloha,
scott
www.turbovans.com

----- Original Message -----
From: "HotelWestfalia" <zolo@FOXINTERNET.NET>
To: <vanagon@GERRY.VANAGON.COM>
Sent: Sunday, May 01, 2011 12:24 PM
Subject: Won't run, yet I got 12 Volts ...

I'm trying to run the windshield washer bottle's pump.  Pulling the arm, I
got 12 Volt reading but the motor won't run.  Took it out, tried it with a
battery's power and it was running great.  Now, I can only think of that the
12 Volt I got is not powerful enough.  How do I measure if it has enough
power?  And how am I going to improve on it?  Apparently not every 12 Volt
is as powerful as the other.
Not understanding it yet.
This is an '88 Vanagon, A/T.
The List is my only help, other than myself and the Vanagon Bible.
Zoltan