I’ve been thinking about this and am well on my way to writing a thesis on the Lucas 6 Watt and 16 Watt wiper motors that were used on the 410s and 411s respectively.
Brian - Your 410 wiper motor is behaving exactly as I’d expect it to, I don’t think any previous owner has changed anything. You are bypassing the limit switch when you ground terminal 5. The limit switch goes to ground anyway and opens in order to stop the motor when the wipers have reached the park position. So bypassing it means that you are causing the motor to run on slightly beyond the park position before it then then starts the next sweep. You have to keep your finger on the switch that you are using to ground terminal 5 for long enough allow the limit switch to close again to allow the sweep to continue. You are quite safe in grounding terminal 5 because that is only ever connected to earth via the limit switch. THIS IS NOT TRUE OF THE 411 WHERE TERMINAL 5 CAN BE LIVE IN A NUMBER OF CIRCUMSTANCES- the 411 motor and it’s wiring and it’s switching logic is entirely different to the 410s
The change between the wiper operating arc and the wiper parking arc is achieved by 1) a degree of play engineered into the crank arm that drives the rack that runs to the wiper wheel boxes 2) reversing the motor so that then drives the wipers in a different arc. Each motor reversal between slow-to-stop and stop-to-slow has to take up this play which is why you get the 2/3rds wipe before the wipers then take up the full wipe pattern and also the 2/3rds wipe before they shut down
You could perhaps build a timer and a relay into your circuit to give a timed operation of the wiper off a single tap on your momentary toggle switch
|