Stopped in at an auto electrician's on the way home tonight. He suggested a dead simple way to wire up DRLs.
Very similar to Kris' (aka Statek) suggestion earlier actually.
Find a wire that provides power when the ignition is on (preferably not when on Acc unless you like being parked up at night with DRLs on as well as the radio). That's what the black "Con Fan" wire I'm using does.
Hook that directly to the DRL's positive side to provide them with power.
Then take the negative side of the DRLs and hook that up to the power wire for the headlights. On my 89 AW11 SC it's white and red.
No relay needed. No diode either. When the ignition is on but the headlights are off, power flows from the "Con Fan" wire through the DRLs and finds earth through the headlight circuit. But when the headlights are switched on, that earth is no longer an earth so the DRLs turn off. Simple.
Sparky told me they do all DRLs that way. No need for a relay as the current draw is b.a. eh.
So I went home and tried it and yep sure as eggs it works perfectly. Simple. Nice.
