This particular question can have a different answer (as I understand
it) when it comes to Subaru conversions.

If you have a Subaru conversion, then the Subaru list is probably the
better place to seek info for wiring up an aux battery or using the
fridge relay.

Mike

John Bange wrote:
>> I almost hate to ask this question.  I am adding a relay and aux battery
>> to
>> my passenger van.  The relay came from a weekender and I currently
>> have my
>> 2
>> batteries connected directly together and not using the relay.
>>
>> So my question is can the relay tell the difference between battery
>> voltage
>> and charging voltage (I wouldn't think so).  But if not what triggered
>> the
>> relay to close only after the van was running.
>>
>> Clarification is greatly appreciated, but please no wiring diagrams or
>> big
>> words.  I liked the way the relay worked in my dual battery camper and I
>> would like to set it up to work the same way in my new van.
>
>
>
> In a nutshell? The aux relay is powered off the blue wire coming from the
> back of the alternator. The blue wire shows voltage only when the
> alternator
> is charging.
>
> It  gets more complicated* than that, but it all basically starts with the
> blue alternator wire.
>
> *My own setup: blue wire triggers "alternator working" relay, which
> supplies
> 12v to coil of solenoid-type aux battery relay. The solenoid coil grounds
> through the NC contacts of a "starter in use" relay which is activated by
> power to the starter solenoid, thus disconnecting the aux battery while the
> starter is cranking.