Williams World Cup, the System 3?
If so, here's a pic of a System 4 MPU, which is similar. The negative side goes to the connection that touches the large ground plane on the perimeter of the board.

http://www.pinwiki.com/wiki/index.php?title=File:WMS_sys4_MPU_board.JPG

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Chris Hibler - CARGPB #31
http://www.Team-EM.com
http://webpages.charter.net/chibler/Pinball/index.htm
http://www.PinWiki.com - The Place to go for Pinball Repair Info

Well...I am.
And I've done hundreds of them.
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Chris Hibler - CARGPB #31
http://www.Team-EM.com
http://webpages.charter.net/chibler/Pinball/index.htm
http://www.PinWiki.com - The Place to go for Pinball Repair Info

And if in doubt, use a meter with power on before you solder on the wires.. You will see +5 (or something close) if you chose the right pins.

image.jpg
use a 4 battery holder and solder the diode in the battery holder

...with the banded side of the diode pointing toward the positive connection.
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Chris Hibler - CARGPB #31
http://www.Team-EM.com
http://webpages.charter.net/chibler/Pinball/index.htm
http://www.PinWiki.com - The Place to go for Pinball Repair Info

No benefit other than you can see that there is a blocking diode installed. The diode stops the batteries from being charged when the machine is ON. So on a three battery pack you will just have a diode in line with the positive wire. The banded side nearest the board the unbanded side nearest to the pack.

Your board is trying to charge whatever batteries it finds but typically you will not be using rechargeable batteries and you can damage regular batteries if you let it try to charge so the solution is to add that diode, it stops the charge.

Why are there 3 wires soldered to the board in this picture?

My guess, the 3rd is a ground wire to bulletproof old Gottliebs. It goes back to the frame of the power supply.

Has anyone replaced the three batteries in an Addams Family. If so can you post a picture so I can see how to do this. Thanks.

Your TAF is a WPC-089...
See this... http://www.pinwiki.com/wiki/index.php?title=Williams_WPC#Relocating_the_battery_from_the_MPU_board
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Chris Hibler - CARGPB #31
http://www.Team-EM.com
http://webpages.charter.net/chibler/Pinball/index.htm
http://www.PinWiki.com - The new place for pinball repair info

As noted, that's a ground mod wire.
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Chris Hibler - CARGPB #31
http://www.Team-EM.com
http://webpages.charter.net/chibler/Pinball/index.htm
http://www.PinWiki.com - The new place for pinball repair info

yep that is a ground wire i added

My two cents, if you intend to install a battery remote instead of an NVRAM:

1. Run the wiring for the remote all the way from the MPU to the coinbox, and leave the remote in or on your coinbox. That way, when you need to check or change your batteries, you'll only need to open the coindoor instead of moving the machine, removing backglass, possibly damaging backglass, etc.

2. Install molex connectors on the remote wiring 6-8" off the MPU. That way, if you ever need to remove the MPU or send it out for servicing, the remote is easily disconnected.

Not to bad if you can solder . FWIW nvram will not hold your time and date.