fin:

normal for voltage to go down somewhat under heavy electrical load. see if
you can check voltage across battery terminals before starting, and then
under load at cruising rpm. before starting, volatge should be about 12.25
V. at cruising rpm, any voltage above this value means battery is
charging, albeit slowly if less than 13 V or so. acid test (please exuse
pun) is to check battery fluid with hydrometer, and if ok, then charging
is adequate. if condition has been going on for many trips and van still
starts up easily, that itself is evidence charging adequate.

dan

On Thu, 15 Jul 2004 09:34:29 -0700, Fin Beven <FinBeven@MSN.COM> wrote:

>Here in SoCal during the summer, it's often a long, hot drive from LA to
Bishop up Hwy 395.  North of Mojave there's a stretch where they encourage
you to turn on the head-lights, even in day time.
>
>The lights, the heat, and the A/C cause my voltmeter to drop from a
typical 13+ volts down to less than 12.
>
>I would have thought that the voltage regulator would compensate for
this, but apparently not.
>
>Has anyone experienced this ?
>
>Has anyone experimented with upgraded alternators or more sophisticated
voltage regulators ?
>
>Thanks,
>
>Fin Beven
>'90 Carat, Custom Camping Conversion
>Pasadena, CA