I actually did this on my W114 many years ago when I mounted a new electric Chevy Cavalier washer pump just above the bulb. Took pump power directly off the original pedal switch. I had to clip the wire that cycled the wipers from the pedal as the wiper circuit was feeding back through the pedal-switch to run the pump constantly if the wipers were turned on. No big loss as I simply remembered to turn on the wipers briefly if I needed the washer when it wasn't raining.

Happy Motoring, Mark

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DrDKW