Harold & Darrell,
I reproduce the chart below from the Haynes Automotive Electrical Manual
(p.67):

Metric Size mm2                    AWG Size
    .5                                        20
    .8                                        18
    1.0                                       16
    2.0                                        14
    3.0                                        12
    5.0                                        10
    8.0                                          8
    13.0                                        6
    19.0                                        4
    32.0                                        2
    52.0                                        0

Bill
90 Westy Syncro
-----Original Message-----
From: harald_nancy <harald_nancy@EARTHLINK.NET>
To: vanagon@GERRY.VANAGON.COM <vanagon@GERRY.VANAGON.COM>
Date: Sunday, January 24, 1999 6:14 PM
Subject: Auxilliary battery relays and wires

>Darrell,
>In the Bentley I have 1980-91 on page 97.4 how to
>read wiring diagrams.
>It says on the left towards the top with the line pointing
>to a sample:
>
>Wire size/color
>American Wire Gauge (awg) as shown, or
>metric cross -section. Example:
>1.5 (mm);
>color code correspond to wire colors in vehicle.
>
>So my interpretation of this mystery is:
>sometimes a diagram will show the standard american Gauge.
>Like  4, 6, 12, 14,  etc.
>As the number is smaller, the wire is bigger.
>A 16 is puny compared to a 6 gauge.
>
>But on most diagrams in the Bentley the numbers are things like
>0.5  and   2.5    and the the big one  a  6.0
>Those are the millimeter cross section of the wires.
>If the number is bigger, the wire is also bigger.
>
>I guess one could measure the metric ( the core ),
>then match that to the standard american gauge.
>On a package of wire that I have here, it shows that
>16 Gauge is equivalent to 1.0 mm.
>Perhaps someone can come up with a chart.
>Harald
>90 westy
>
>Darrell wrote:
>> > Hi Harold,
>>     Thanks for the enlightenment about the relays. One more big problem I
>> have is in my bentley on page 97.4 (how to read diagrams) and 97.5
>(Symbols
>> used in wiring diagrams) it states that the numbers on the wires are in
>AWG
>> or american wire gauge.  I feel this is true until about 85 wiring
>diagrams
>> then they switch to some system that I am not familiar with.  I realize
>many
>> bentleys are different, probably as many different bentleys as there are
>> versions of the other bible. I think I understand AWG sizes but I am one
>of
>> the old farts on the list and maybe missed something in the last 10 years
>> that changed in the AWG sizes. I see wire sizes listed as 6.0 and fused
>with
>> a 50 amp fuse and 0.5 fused with a 10 amp. There are battery ground
>straps
>> at 25 and battery to starter straps that are 70.
>>     In the old days 10 awg was 30 amp max 12 was 20,  14 was 15. If you
>> understand the new awg system bentley switched to in about 85 please
>> enlighten me again. tia
>> Darrell
>> -----Original Message-----
>> From: harald_nancy <harald_nancy@EARTHLINK.NET>
>> To: vanagon@GERRY.VANAGON.COM <vanagon@GERRY.VANAGON.COM>
>> Date: Saturday, January 23, 1999 10:45 PM
>> Subject: Re: Isolator, where to put it?
>>
>>
>> >Greetings,
>> >With regard to relays in "campers":
>> >"3-way refrigerator relay":
>> >The 2 vanagon full westfalia campers ('81 and '90)
>> >that I have owned only had the little "refrigerator relay",
>> >as shown on page 97.33b in Bentley.
>> >That relay (called 12 volt refrig./heater relay) is mounted
>> >under the driver's seat.
>> >In my opinion, that relay is not intended by VW to
>> >also run an aux. battery in addition to the refrig.heating element
>> >(which actually can draw quite a bit), even though
>> >it is mounted in that empty battery box.
>> >
>> >"Auxillary battery relay'':
>> >The "auxillary battery relays" mentioned in the Bentley:
>> >(In my Bentley, they are on pg.97.34a, pg.97.222, and pg. 97.225.)
>> >These relays are intended for a second battery, and are
>> >designed adequately by the german engineers for that purpose.
>> >The point is that those relays are different from what we have in the
>> >full westfalia camper with the 3-way refrigerator.
>> >
>> >The 2-battery setup with that stronger relay is what VW
>> >used on the "weekender camper", that has only an
>> >electrically powered refrigerator.
>> >Those vanagons probably were delivered with 2 batteries in place.
>> >
>> >If someone wants to convert their westfalia full camper to
>> >a dual battery setup with a relay, they could go to the dealer
>> >and purchase that stronger relay that is shown with the dual battery
>setup.
>> >And then install the bigger size wire, and perhaps install
>> >an additional 30 or 40 amp fuse, and that setup should be ok.
>> >
>> >In summary, all that I am saying is that the "refrigerator 12 volt
>> >heater relay" for the 3 way frig. is not the same part (and not as
>strong)
>> >as the dual battery relay used for the weekender package electric only
>> >refrigerator.
>> >
>> >Harald
>> >'90 full camper westy
>> >
>