BMW E39 wipers not working – wiper relay
E39 wipers not working – what is the most common cause?
Often the fault is the wiper relay, whose contacts are worn. The relay is replaced first. Cleaning the contact surfaces has helped in some cases. If the relay and wiring are fine, the fault is probably in the body control module.
Where is the wiper relay and is there one relay or two?
The relay is on the passenger side under the fresh air housing, in the electrical box. Before 9/1997 there are two relays; from 9/1997 there is one shared double relay. Access requires removing the fresh air filter housing.
Why do the wipers stop in the middle of a sweep?
The cause can be the wiper relay or the wiper motor's limit switch. A loose nut in the wiper linkage has also caused the same symptom.
What if the rain sensor does not work?
The rain sensor may start working after a reset. Fault codes show whether something else is wrong. Erratic operation of the sensor is usually not caused by the wiper relay.