Relay Box Question, Where does the black wire go?

[CSM]

So... In the relay / bus box on the drivers side behind the battery. There are two leads, going into the box. A red one, and a black one. The red wire, goes to the drivers side battery, and the black one goes where? I can't seem to find it on any of the wiring diagrams. (if i am missing it on one of Mike's diagrams, please help) I am showing 12V on the black wire as well as the red, and before putting a DVM on it I had always assumed it was a ground. Does it go to the curbside battery? http://forum.mopar1973man.com/attachment.php?attachmentid=1689&d=1301768556

[dripley]

i am no electrical genuis by any means, but it appears to come from the alternator. it must be the main feed going thru the fuse to the electrical system. i am sure some one will correct me if i am wrong.

[CSM]

I was just thinking that... Makes sense. I was kinda confused earlier when I put the DVM on it and it showed 0V from the red to black. I also think I found my voltage woes... Bad voltmeter. I went and used a couple from work, and lo and behold, my DVM shows 18-19V (symptomatic of an overcharge) and the two DVMs from the shop show 12.5V when the truck is off and 12.9 - 13.9 when the truck is running. The bad part, is that I still don't know why I have burned out multiple Edge chips. :banghead:

[dripley]

i am always:banghead::banghead: when it comes to electrical. iam getting a little better but i sure hate practicing because that usually means something is wrong. went thru to much of that when my ecm took a dump. i saw your post on the frying the edge chips. i just dont know enough about that to offer anything. but it looks like we both learned something today any way.

[ISX]

Yes the red one goes to the battery which feeds the whole shpeil of fuses. The black goes to the alternator and crosses to the red one via the 120 amp fuse in between the 2 screws as you have shown in the pic. That red one actually feeds EVERYTHING. The starter and grid heater are the only things that don't tax the red wire since they tie directly to the positive terminal of the battery with their own wires.