Electrical System Battery Isolating Switch

As of approx. 06/93, vehicles which are shipped overseas are equipped with a battery isolating switch. The ground connection is interrupted by the battery isolating switch. This prevents the battery discharging due to quiescent current consumers in transit and when the vehicle is laid up for long periods.


NOTE: On model 210 the battery isolating switch is connected to ground (battery) (W10) in the right rear seat footwell.


NOTE: Do not switch the battery isolating switch to the "Off" position when the engine is running. Interrupting the voltage when the engine is running can result in considerable damage to the vehicle's electrical system. This damage is not covered under the warranty terms and should not therefore be submitted as a warranty case under any circumstances.


Notes on handling battery isolating switch with infrared remote control
It is absolutely essential to comply with the following operating sequence to interrupt the voltage supply with the battery isolating switch on vehicles with infrared remote control.

Models 202, 129
1 Open trunk lid or tailgate.
2 Close driver's and front passenger's door.
3 Lock vehicle with infrared remote control.
4 Switch battery isolating switch to the "OFF" position.
5 Close the trunk lid or tailgate.

To switch on the interrupted voltage supply, unlock the trunk lid or tailgate with the key (mechanically), switch the battery isolating switch to the "ON" position and lock the trunk lid or tailgate again. Then unlock and lock the vehicle again twice with the infrared remote control.

Models 210
1 Open right rear door.
2 Close the trunk or cargo space, left rear door and driver's and front passenger's door.
3 Lock vehicle with infrared remote control.
4 Switch battery isolating switch to the "OFF" position.
5 Close the right rear door.

To switch on the interrupted voltage supply, unlock the front passenger's door with the key (mechanically), switch the battery isolating switch to the "ON"position and lock the door again. Then unlock and lock the vehicle again twice with the infrared remote control.

Notes on removing and evaluating battery isolating switch
The battery isolation switch must be removed before the vehicle is delivered to the customer.

The following work should be carried out after removing the battery isolating switch and connecting the ground cable to the negative terminal of the battery or to ground (battery) (W10):
- Code the radio
- Adjust power windows to standard position
- Adjust the time on the stationary heater if necessary
- Reactivate the steering angle sensor on vehicles with ADS

Returning the battery isolating switches removed is only intended for countries which are connected to the exchange parts return shipment system of the Central Parts Department, Germersheim. The parts department provides information on the method of return shipment. The battery isolating switches should be scrapped in other countries.