Hoping for some electrical help

Hey everybody, i am a new member, but have been reading ever since i bought my 92 s10 blazer tahoe two years ago. I am most recently putting a 5.3 vortec into it, and have run into a problem. While removing the old 4.3 TBI, i cut the harness to the old computer, aswell as at the firewall, engine connector. the swap continued, and when i got back to wiring, and went to re establish power to the original fuse box, (brake lights, blinkers, etc etc,) i ran into a huge hang up. I have power to the truck, by grounding the large 12 guage black, and powering the large red, but everthing appears jumbled. The stereo comes on when i press the brakes, then turns off when the headlights come on. THe blinkers don't work, and the rear wiper only works when the interioir lights are manually turned on. THere are several other "jumbled" electrical situaltions, just about everything works, but only with a maze like combination or switches and things turned on or off. Has anyone done anything like this, or have any advice? I am not a newbie, and am very good with mechanics, however this one i can't seem to fix. I have tryed what seems like everycombination of other ground wires, which has effect, but nothing in the right direction. VERY sorry for being so long, kinda complex problem. ANY feedback appreciated.

Welcomw to AF there lurker :grinno:

Well Personally I would just scrap the stock wire harness at this point alltogether!

Contact Painless performance
http://www.painlesswiring.com/
Tell them your problem and ask them to send you out something that's easy to hook and will work.

It's what they do, and they're the best.
Some companies do cost a little less, but you get what you pay for (Service, and good qualith wire / conections)

idk if painless is even needed, sounds like his problem came when he (accidently, in a hurry, or not thinking moment) cut the wiring harness, all you may need is a stock replacment from a bone yard if its not to cold out where you are