Nissan Repair: 1994 Maxima electrical failure, nissan maxima gle, nissan maxima

Question
Hey Von,
      I own a 1994 Nissan Maxima GLE which has had a number of reccuring electrical problems over the years - 4 alternators, at least 6 batteries and 2 climate control consoles have all been replaced.  Two weeks ago I had to replace the battery again because it would no longer hold any charge.  Given the cars' history with alternators I had my mechanic check the whole charging system, he told me it tested out fine once the battery had been swapped.  That same day I performed a routine tune-up myself, changing the oil, plugs, and ignition cables.  Indeed the car was running quite smoothly until tonight, when I first noticed the clock light was dim on startup, but returned to normal brightness seconds later.  As soon as I began driving though I noticed the headlights were randomly changing in brightness, from very bright to quite dim, with no apparent relation to the actions of the engine - what I mean is it would go from bright to dim or vice-versa regardless of whether I was accelerating or stopped at a light.  This continued for the duration of the drive (about 10 minutes) when, as I was about to pull away from a stop sign, the car completely lost power to all systems.  The engine immediately died, as did the radio, and all lights, both internal and external.  I managed to push the car home, however there is still absolutely no power anywhere in the system - in fact my key is still stuck in the ignition because of the key-lock mechanism which won't release it (electrical I suppose?).  Having perused your online FAQ I'm assuming (hoping) the problem is either battery cables, bad ground wire, or possibly a fuse, however given the electrical history of this car I'm hesitant to dive in without some expert guidance.  Given their corrosion I intended to swap the battery cables anyway, but the complete lack of any power whatsoever concerns me greatly.  My Haynes manual suggests the problem might be a fusible link in the panel next to the battery, however I'm unsure of this diagnosis as the manual has been wrong in the past.  Am I looking in the right places here or am I totally off base?  Any suggestions or advice with regards to this problem would be greatly appreciated as I have to get this car running ASAP.  I thank you for your attention to this matter and look forward to your response.  

Answer
Sean,

The cables are where I would start and I would make sure that the connections to the battery were good along with the fuses and fuseable links.  Also, after checking changing and cleaning the cables I would be checking the ignition switch to make sure that the connections are good and the switch is in good working order.  I am sure you have a bad ground somewhere or a bad relay that is causing the problem.  I agree with you that I would start with the cables.