Mercedes-Benz 190SL drivers are doubtless familiar with the shortcomings of the windscreen wipers when driving in light rain: you’re continually having to use one hand to operate the switch. It’s hard to drive like that for any distance. Alternatively, you can ask your passenger to pull the switch.
What you don’t want, however, is another switch on the dashboard. Not only doesn’t it look great, but it’s not authentic.
There is a solution, and that is to fit a relay, activated by the windscreen washer foot pump that you’ll find in nearly every W121 in the top left of the footwell next to the dipswitch.
Step on the pump briefly with your left foot to activate the interval switch. The wiper then operates twice and then once every 5 seconds after that. Step on it again to deactivate the switch. The interval switch is also deactivated when the ignition is switched off. Fitting isn’t particularly difficult. We offer the relay prewired to the wiring harness together with the fitting instructions. We would also be happy to install this interval circuit for the windscreen wipers in your Mercedes-Benz 190SL.