I have an idea to replace the 2 speed switch with a 3, but I'd like to keep the original Knob on the new switch so want to take it off to measure up before buying a new one.
If this is possible there would be an additional (spare) position, O would become the 1st On position and be used for a new extractor fan/s, 1 & 2 would be as now.
I've proven the extractor works with a cheap £5 fan, lit a Smoke Match in the passenger footwell and it pulled all the smoke out easily. Just pushing around ideas on how to elegantly implement.
