300zx electric shutdown

[94VG30DE]

Ok, so I was on my way back up north from home last night, and had been driving my 94 300zx NA with 96000 miles on it for about 3 hours straight at that point. My average speed for the trip was around 85 mph, not driving terribly hard, just cruising along open 3-lanes. At one point, I put on my brights and the car freaked out. My head unit shut off, ALL my lights shut off, and the car basically died for about 1 sec. I felt it stall (for about 1 sec), and then everything caught up and started running fine again. I kept driving it, and tried the same trick (turning on the brights) periodically over the next 45 min it took me to get home. My car has numerous other electronic problems other than this, but they are things that simply do not work all the time, not features that dont work when I use other features in conjunction. They are all cosmetic things, such as dome light not working, airbag light stays on, door dingers don't work, etc. I was wondering what I can do to fix this problem, and what indeed the root problem is. thanks.

chris