BMW E34 wipers and washers: common faults
Why do the E34 wipers keep running or not stop?
The cause is usually the wiper relay, a fault in the wiper switch (the stalk) or a fuse. The relay is in the relay module under the rear seat, and the fuses related to the wipers are 22, 24 and 44. If replacing the relay or the stalk does not help, the fault may be in the general module.
Why do the wipers stick or wipe poorly?
The linkage joint has dried out and rusted, or the brass bushings inside the arm are worn. Greasing or new bushings help. Ball joint rods are not worth refurbishing, buy new ones. The wiper blade rubber must be perpendicular to the glass.
Why do the wipers work only at the fastest setting or only as a drizzle wipe?
A fault at the fastest setting can be caused by the power supply through the main fuse, so check the fuse and the harness connectors under the rear seat. If only drizzle works, the speed-dependent wipe is not getting speed information. Start with the connectors and wires of the sensor at the rear.
Why does the washer pump not deliver fluid?
The pump's power wire may have come off. Before replacing the pump, check that power reaches the pump, and look at the relay and fuse.