From the factory the 90 amp alternator was already an upgrade to support AC
and the larger radiator fans that went with it. It is plenty sufficient
until crazy loads are added. As for over current protection there are things
to consider including avoiding nuisance disconnects, especially lighting,
ignition, and fuel delivery. The Europeans use a separate fuse for head
filament and the rear is split left-right. The Americans use a
self-resetting breaker for the headlights so you get the lights flashing in
case of an overload. Fuse links are also an option for the larger wires.

How much re-engineering do we want to do? What is there has worked for 22+
years.

A consideration for increasing the alternator capacity is "driving" it. The
single belt can only transmit so much power and with the limited wrap around
the drive pulley makes things worse. Even 120 amp alternators make for very
short belt life. BTDT.

Dennis

-----Original Message-----
From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf Of
Bret Berger
Sent: Thursday, November 21, 2013 1:43 AM
To: vanagon@GERRY.VANAGON.COM
Subject: Re: High beams not working-lighting upgrades!

Sounds like a good reason to install a properly sized fuse inline with a
wire gauge upgrade.  Perhaps an alternator upgrade would also be in order?
Any voltage drop across your headlight/radiator fan/blower motor supply wire
implies waste heat being dumped from the wire.  Power = current x voltage.
A 2 volt drop in a supply wire with a 20 amp load is
40 Watts wasted.

On 11/17/2013 6:35 PM, Dennis Haynes wrote:
> Most auto equipment will work over a large voltage range but
> performance does suffer. However it is not by accident or even cost
> savings that the wiring is "undersized". As the system gets loaded
> down thee resistances help to control the load on the alternator.
> Also, as so much wiring is not over current protected the smaller
> sizes also help to limit or control fault currents. Yes those wires
> can act as fuses hopefully burning up enough to open before the van is
gone.