Well the other day I went to start my rig, everything powered up fine..that was until I hit the starter button. The starter clicked once and everything went dead (and I mean everything). I do have my own custom built wiring harness in the rig (for all the aftermarkets stuff on it), but it gets it's power right off of the mater battery switch and I've never had an issue with any harness that I've built over the last 4 years (I don't expect anyone to be albe to help me with my custom harness, since that's my mess). I've managed to find that once I turn the ignition (still stock on the steering column) into the run position all the power to everything still on the stock harness is dead (put hte test light on the alternator and on every fuse in the fuse box to confirm this) and all the power to everything else is gone also (again the stock wiring harness pulls it's power from the same master battery switch). What I'd just like confirmation on is if it's possible for a ignition switch (if it's fawked) to short the rest of the system out? The only other thing that I could see is that it could be something fired in the alternator. Either way something is pulling a good amount of juice and there's not enough power to even turn on my fuel pump (noice out of the relay and that's it).
The day before I was welding on the front of the truck, I had the MSD unplugged, but did not have the neg off of the batteries, but the master was off. There is still 12.84 volts in both batteries and in the system up to the mater battery switch.
I hope this makes sence.

did you check the mester switch and make sure its not bad

I checked it and actually swapped in a spare switch that I was 100% sure was in working condition. I got the exact same results with both switches.
I'm sure that it's gotta be an issue somewhere in the steering column or ignition switch. I can't see what else it could be. all the grounds are good (and brand new). The only thing that I can also think of is that when I was welding on the front end it fawked something up, but I was welding a bracket on for a steering box brace at the front of the frame and wasn't a big job. Also there were no wires at all in that area that could have been melted from the heat.
This really gets to me cuz it was running fine without a single problem last week.

More than likely its the ignition switch. I would pick one up from the parts store & try that..
I'm talking about this part by the way..
http://www.partsamerica.com/product_images/img/nie/ks6623.jpg
not the key mechinism..

Cool I'll try that. I was actually going to try changing the key mechinism, but what you are saying makes much more sense.

Its quite common for the ignition switches to burn out over time, especialy older vehicles (late 70's to the late 80's)

check your power cabels especialy at the starter. try to jump your starter, if it goes its a switch prob, if not you may have burnt the fuse-able link of the main.

check your power cabels especialy at the starter. try to jump your starter, if it goes its a switch prob, if not you may have burnt the fuse-able link of the main.

Someone else told me that also today (about checking the fusable link). I just find it strange that I get power and once the key is turned the power dies. It's going to be hard to work on the rig till firday (with work). But I've got a lot better of an idea of what I need to look at/for in fixing this problem.
Thanks for the ideas/tips

Remove cables from battery, clean, reinstall..........you might just get lucky. My truck has experienced the exact same issue several times and it's always been due to loose or corroded battery terminal.

Remove cables from battery, clean, reinstall..........you might just get lucky. My truck has experienced the exact same issue several times and it's always been due to loose or corroded battery terminal.

After checking everythin we finally checked the battery cable again and that was the cause (well bad ground connection). I fell really stupid cuz it was something really simple that took me forever to figure out and ended up making a hell of a lot more work for myself that I had to.
I found it really strange that I had no problems at all through out the whole summer (truck would start very easy with lots of juice, as well as lots of juice in the system all the time without any issues), to letting it stil for no more than a week and then it being completely dead.