Please help. My 2000 S40 will sometimes lose all electrical, I mean ALL, not even interior lights work, everything on the dash goes off, I turn the key and NOTHING. It is random, it's been fine for about a month and today it did it twice, after turning ignition on and off multiple times it eventually starts, when it does the clock and trip odometer always reset but the radio doesn't, I have checked battery connections (new battery by the way) I have tried moving wires to see if it's a bad connection and nothing works, has anyone had this issue? Could it be the ignition? Where do I start? Thanks in advance.

 

I am having the same issue, except now my car doesn't start at all, nothing happens when I turn the key, just a click. I still haven't found some one with a solution. Marc

 

Complete loss of electrical is actually pretty easy to troubleshoot. You start with a volt meter or even test light at the battery and convince yourself that the battery cables are live or not (puncture the insulation). If they seem okay then start through the fuse box with your test light.

What will happen is that the power will come back on while you are monkeying around, so be sure leave the car in a condition that it'll alert you if it can (like leave the wipers on and ignition on). When that happens you'll have a clue where the problem is.

If you are describing this accurately (intermittent loss of all power) then the problem is a bad connection on the battery cables, probably caused by corrosion on the battery terminals.