Jim, I've still to investigate,but I suspect I have a defective switch.
I recently hooked up my new loom, followed the instructions to the letter and guess what,it doesn't appear to work.
Mine came from Truckandcarshop.com
Cheap ROC trash....
With the knob pulled out to full extension it flaps about terribly,I have no park,dip or main beams,plus the dimmer function doesn't work.
The rear park lights work fine.
What is this Cole Hersee switch? Care to expand?