Anybody know what secret series of switch actuations will toggle the DRL on?
My 08 Limited has the DRL option; the headlights automatically come on at about half power whenever I take it out of Park. Day time or night time. The DRL is a factory installed option and is not standard equipment.
I got the official answer from an acquaintance who works for Ford.
The body computer needs to be queried by the Ford Dealership scan tool and have the DRL function turn on. That operates the front fog lamps at full intensity on 2007s when the engine is running, the transmission lever is out of Park, the parking brake released, and the healamp switch in the off or auto position.
My 2008 does not use the fog lights for the DRLs. It uses the headlights and you can't shut them off...even when you would like too.
Only the 2007 Expedition used the fog lamps for DRLs, and that was only standard in Canada where the federal law requires DRLs. The use of fog lamps as DRLs is prohibited by federal law in the US because each of the states regulate fog lamps performance and operation and none wanted fog lamps to be used as DRLs. Thus the federal law prohibits it.
That is why the 2008 Expeditions sold in the US, use the lower beam headlamps in a dimmed mode, as DRLs. The reason that you can' shut them off unless you are parked is because the Canadian law requires it that way, and US law doesn't requirie them to be capable of being shut off. It leaves that choice to the vehicle manufacturer. Thus, Ford and other have chosen to make only one version of the vehicle as regards to DRLs. Their choice is the Canadian wiring version.