The Subaru alternators naturally have low output voltages at idle. No
alternator produces full output at idle. Rev the engine up to about 1,600
rpm to see if the voltage increases. Also, the Subaru alternators will
reduce available output as they get heated up. This doesn't indicate
anything wrong, it is just the way they work.

Dennis

-----Original Message-----
From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf Of
Steve Williams
Sent: Friday, September 04, 2009 12:37 PM
To: vanagon@GERRY.VANAGON.COM
Subject: Only 13V from Alternator

I've known for awhile that the batteries aren't getting charged while
I drive.  The ProMariner has been saving me: It charges the batteries
each night while I'm parked.

But I just measured the alternator output at idle and at 2,000 rpm:
13 volts.  My understanding is that it should be 14.2-14.4 volts.

So, is it pretty easy to replace just the regulator on the
road?  Somebody point me to a how-to?  (It's mounted on the alternator,
right?)

Or should I bite the bullet and just get a whole alternator with the
integrated regulator?

I'm planning to drive some remote stretches on the way back to
California, and I don't want to get stuck.

http://twitter.com/sbwsty

Thanks.