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Sun Jun 01, 2003 11:38 am

Hi!

I'm looking to add a second fuse block for my accessory items (CB, Fan, XM Radio, etc). Has anyone done this? What gauge wire? Where do I run it from? Thanks for the input!

-=Rob
'77 Westy

Sun Jun 01, 2003 12:45 pm

Take a look at your wiring diagram and you'll see what size wire VW chose for various accessories and electrical items. Use this data to convert from the German sizes to AWG:

http://www.dolphinsci.com/vw/wires.html

This guide will tell you how much current the wire can withstand:

http://fp1.centurytel.net/chzweeth/cpw-em1.htm

Find out the power requirements for each item, compute the current in a 12V system (I=P/V) and pick a gauge of wire that can take the current and then fuse it appropriately.

Mon Jun 02, 2003 8:04 am

I've added a fuse block inside my sink cabinet. I ran a 12 gauge wire (I think it was 12, can't remember- it was larger than the wire coming from the dash) from the second battery to the fuse block. I then wired my sink pump, flouresent light, two cigarette lighter sockets (one on the sink cabinet one near the back), and a gooseneck reading light for the rear. Just be sure to use the appripriate fuse and shut off any accesories as it's constant power off the second battery.

My personal opinion is to run a large wire to the fuse block (less resistance and that's a long way to the front of the bus) fuse it appropriately and run whatever wire came on the accessory. I've thought about upgrading the power wire for my headlights too. ie run a heavier wire to them and then use a relay on the switch to cut your voltage drop.

Mon Jun 02, 2003 1:56 pm

Ok I'm cool with the size wire and all. The last question I have is where do I run it from? Directly from the battery? What about the ground? Thanks for the input!

-=Rob

Mon Jun 02, 2003 5:36 pm

Yes, you can run it directly off the battery IF you want constant power, otherwise you need to wire a switch in line or bring it off of a switched line. The ground can be anywhere you get a good contact- try to keep your ground as short as possible though. Remember, the more wire the juice has to travel through, the greater the resistance so you need to up the wire gauge as you get further from the source. If you run it off of a second battery, you don't have to worry about killing your starting battery.