All Electrical is cutting out intermittently, now cut out completely
 

I have a 98 V70XC with an electrical problem that has quickly elevated past the annoying thing that I can ignore phase.

- I first noticed a few weeks ago that the radio and trip information indicated that they had lost power while parked overnight, since I had to re-enter the radio code and all the trip information was at zero. I hoped that it was a weird fluke and I could forget about it.

- A few days later, everything lost power when I got out of the car and shut the door. I noticed the power locks didn't work, then checked everything else and no power. I got in and shut the door and power was restored. This happened for a week or two and I was hoping I could still ignore it.

- One day, all electricity cut out while the car was running. I assumed a bump did something similar to the the door shutting.

- A few times this past week, I had to slam the door quite a few times for the electricity to come back on. Sometimes, the dash displays would show odd digits (not all 8s), then I would put the key in and turn it, then everything would cut out again. It almost seemed like if I had the key in and turned when I shut the door the first time, I had to have the key in and turned when I shut the door to get electricity again....this may have been a coincidence.

- Today while going to lunch, it stopped responding at all. I slammed the door about 10 times and gave up. I came back later and tried another 10 or so times. Then thought I might be able to bang around the ignition switch and get a response (my parent's Saab needs this sometimes), but still nothing.

Has anybody heard of anything similar to this, or have a suggestion of where to look first? I'm an electrical engineer and am generally not afraid of digging into electrical issues, but it takes a long time to find an open connection if you don't know where to start.

Also, please don't confuse an electrical open and an electrical short. It drives me up the wall. I know that almost everyone uses short not knowing that they should really be saying open, but please don't say short when you mean open.

I should also note that the driver's switch for the left rear window was not working for up. It started working again about the same time that this all started. Might just be another coincidence.

I disconnected and reconnected the battery and all electrical returned. I'm guessing this is a case of a short causing a relay to disconnected power from everything that I could notice. From what I had seen in other posts, I thought this only happened with certain parts of the car and not the everything. Does anybody have any suggestions of where to start looking for an intermittent short?