'94 E320 - Intermittent turn signals

[Redflash]

The turn signals on my wife's '94 E320 stop working at times after selected. I got the system to stop functioning after activating the emergency flashers for a period of time (about two to three minutes), but I have not been able to get the same result with putting the turn signals on, either right or left.
The fuse(s) are all OK, and the relay unit appears to function OK as well. I pulled the cover off of the relay unit and there are no apparent signs of problems with the relays or any of the electrical components on the pc board.
Could this unit be "overheating" and shutting down all turn signal/emergency flasher functions?
The threads I read while trying to research this problem seem to indicate the emergency flasher switch may be the guilty party, but I have not removed it.
Any ideas or suggestions? Thanks.