I would avoid using the AC in stop/go traffic until the fan assembly has been replaced. High temperatures are not only bad for the engine but they are worse for electronics/wiring. As it is, the electronics in these cars are hanging in there by a thread
If one fan has gone bad, the other one is probably on the way out as well. You can tilt the radiator to get the fan assembly out. Should take maybe 30 mins.
The fans on my car were running slow and intermitently blowing out the fuse.
These fans have been refered to as "garbage cans" on these forums, as they were a bandage, to update the W124 without changing the architecture.
Above 25 mph, the W124 does not need any cooling fan under normal conditions.