I have a 2013 Prius c and want to change the fog lights to be daytime running lights instead. I'm sure there shouldn't be too much of an issue changing the actual bulb to LEDs, but I'm wondering if there's any easy way to change to switch so I can have it turned on all the time, regardless of the parker/headlight setting. As it stands, I at least have to have the parkers on to have the current fog light turned on. Thanks, Joss
Check out this YouTube video, this guy did what I did, made his highbeams reduced power DRLs, using some relays: I think you can just reverse the highbeam and lowbeam input wires in his diagram, and instead of connecting the outputs to the highbeams, connect to your foglights. Then you will end up with your foglights that operate at half power as DRLs (less heat, less power consumed, better visibility during bright daylight conditions) and operate at full power when your lowbeam headlights are on. The foglights would also turn off when highbeams are on, which is what oem foglights do. There's links to circuit diagrams and parts lists. There's a link in my signature below too, on how I did mine. LED bulbs designed for nighttime use don't really show up well in bright sunny conditions. Halogen bulbs a reduced power are much more visible (warmer color temperature) than pure white sunlight. Using yellow halogen bulbs in your foglights will make them even more visible during the day at half power
Wouldn't that make the DRL really highly angled? Still dazzling to oncoming drivers, even with a lower voltage?
Yes, you want the higher mounted, wider angle lights for DRL function. The whole point is to be seen. No, that's why they are run at half power. Not blinding during daylight hours, can be bright if used at dusk. Switch to regular lowbeams with cutoffs to reduce glare at dusk.
For what it's worth, if you're planning on installing LEDs, they aren't going to work on reduced voltage. Incandescent lamps (i.e. Halogen... your factory non-LED headlamps) have a simple purely resistive filament...so when you apply less voltage then they just glow with less light energy. LEDs are electronic and designed to operate at a more precise input voltage. If you supply a lower voltage than what the LED driver requires you will not only probably get no light at all, but you might also overheat or damage the driver and kill your expensive LED lamps in the process. Since the Prius C already has reduced voltage DRLs on the high beam lamps, you could T-tap the high beam lamp wires and parallel a relay with a 6-12V coil (not just a 12V coil...I don't think that would fire) and use the output contacts to fire your relocated DRLs. That would essentially bypass the entire fog lamp control wiring though... but you'd get key-on full voltage DRLs if your stalk is in the DRL position. Turning the stalk all the way off would turn your DRLs off too. It would seem that you would need to source a new key-switched 12V wire to fish out to your DRLs for the positive power source. I've seen some cool midget fuse adapters that you could use to pick up that power from your existing fuse box w/o having to pull a fused wire all the way from the battery for your 12V+ source.
