Last night when driving my '87 300sdl, the gauges all went dead. Everything was working correctly, all gauges working. We had to make a stop, and turned on the 4-way flashers. When we went to leave, we switched off the flashers, and now the gauges are dead, temp, fuel, speedo, tach- nothing works. Any ideas?

This is a low mileage (130K) sdl that has been free from any electrical gremlins in the past, so I'm not sure where to start looking. All fuses are good, and I "jiggled" all of them around in case one was loose or corroded. I appreciate any guidance.
Thanks!
Russ