Auto-light question

Yo!

So I got me a switch, and so it didn't get lost, I took it outside and plugged it in. Sides and heads work ok (on instantly). If I put it on auto, there's a slight hesitation and then the heads come on. The car is parked in direct sunlight at the moment which I have read confuses the sensor. (Can't move the car until later, it'll be dark then.)

I did notice, whilst waiting in a car-park the other day, that with the ignition on, if you go to remove the original switch, the heads come on when you move the switch to sides. This seems strange to me, as when removing the switch, you don't even get to sides, let alone heads.

Is it possible that they moved to using 1 loom and had the 'missing wire' installed, and relied on the 'switch and software' solution?