Originally Posted by nakman
This still funnels the whole thing through the hi/lo switch though, but I'm not sure how to avoid that without two more relays- one hi and one lo, which just seems excessive.
That's what the 87A terminal is for on the relay, 87 is NO, 87A is NC. So it takes just two relays. The first is the power on/off and the second toggles between low and high. Bosch figured that out in like 1962 when they designed it.