I have a canadian 2007 lexus rx with the dreaded headlamp condensation issue on the driver's side. An incomplete seal fix propogated more flooding that killed the ballast. I sourced a headlight housing and ballast from USA (oem).

Here is the funny thing.

When I turn the lights on, low beam is on and DRL is off. (both low beam and DRL stays on at passenger side)
When I turn off the lights, DRL is on and low beam is off.

So the DRL bulb on driver side is good, but this does not satisfy canadian regulations that insist on DRL stays on when engine is running. DRL needs to go on when low beam is on. I did not change the relay in the fuse box at all.

Is there some kind of secret relay in US version of the headlamp to cause DRL to go off when I turn on the low beam?