Infiniti :: 1991 - Turn Signal / Blower / ABS Warning Lights Stopped Working

3 weeks ago my father (who died 2 weeks ago) gave me his 1991 Infiniti G20 which he has kept in great condition over the years with the last few being the exception. He's the original owner and I have paperwork from every repair and service it's had. Unfortunately the issue it has now started happening after he passed so I'm not going to get info about how it's been running the last couple years. Now to the good stuff.

When I got the car it was outside under a carport like always (lives near Seattle). I drove the car about 200 miles and then a couple days later I noticed the turn signal stopped working, but not only that there were several things not working. The turn signals (yet hazard lights work), the seat belt motor will not let it roll back across my chest, the blower won't work but the AC and heat still works, the rear defogger stopped, the ABS stopped, and the warning lights and sounds for doors open and seat belts were undone don't work.

Then while driving everything just "clicked" back on for about 5 minutes, then "clicked back off the rest of the drive. The next day I started the car, everything was fine but after waiting a couple minutes for the windows to get defogged everything shut off again. Driving around with foggy windows, no turn signals, and no seat belt across my chest is starting to scare me. Oh, and the problem can turn on and off without the engine on. If I just put the key into the "on" position it will sometime switch between working and not working.

I have unplugged and replugged the fuses and relays on the left side under the steering wheel, I've checked the voltage of the battery (2 years old with 7 year warranty and alternator was replaced 18 months ago) and it was about 12.4. I've tried reading the wiring diagram in the service manual without any luck figuring it out. When I took it to the Nissan dealership they did their scans and couldn't recreate the issue and charged me $100 just for doing the electrical tests.

I want this car to keep going since it has 174,000 miles and runs great (manual trans) so need to figure out whats going on. It doesn't seem like it's a loose wire because the car doesn't have to move for it to go back and forth between working and failing. It sometimes works more often if the car is kept in a garage but even then I'm not sure. At one point in the last year a couple mice got into the trunk but they have since left and I don't see anything in the manual that says they could have effected anything all the way back there.