Could someone with an SR5 measure the resistance values please, or if your in the hills district sydney I can meet up and nut it out, should only take half an hour to chase and measure. I am looking to see if a unit from the states will work (= prettier than the 80's trim pot and should work) but need to confirm the resistance values.
My thoughts are that the ECU is looking for a precise change to the resistance, using any old rheostat doesn't work because its chasing a specific value to allow the voltage step. I the value falls outside the ECU's expected parameters it will assume either a fault or normal state and be shunting to full earth. hence why you get max light level with the plug in or out.
I have already tried throwing some resistors I had laying around across the pins with no luck. Also tried a couple of different rheostats from Corolla and Prado, they don't work either.
There must be someone close by with a 5 that will let me at their switch