I was able to finish the fog light install. I realize this isn't related to hypermiling, but it does involve the car. And if I didn't say anything about it, people would probably ask anyway. So here we go!
My car didn't come with fog lights, so I decided to retrofit them. We're using stock replacement fog light housings, along with a relay box and wiring pigtails from a Prius (in the junkyard) that has factory fog lights. So basically, all I need to do is run some wires to connect the dots, so speak.
However, I decided not to use the stock fog light switch. Plus I went with LED bulbs. The LED bulbs tend to be extra bright, so I got an LED dimmer. Using a rheostat with LEDs can be problematic, so we're using a PWM unit instead.
In the photo below, I'm getting ready to transfer the fog light relay and wiring from the junkyard relay box to the one in my car.
Now the wires are transferred over. You're looking at the backside of the relay box. De-pinning those wires was kind of a pain, because I didn't have the special tool. But the pocket screwdriver eventually got it done.
Power for the fog lights was routed from the main fusebox in the engine bay. There's a battery terminal in there, which is convenient. I'm not a big fan of watching my car burn down. So I used an inline fuse.
At this point, the wiring in the engine bay is done. Here's a shot of the engine bay. That yellow wire is ground for the relay. I could have run it somewhere out of sight, but got lazy.
Now we go inside the car...
The PWM controller has a knob for adjusting the brightness. I decided to install it on the kick panel below the steering column. It won't be used very often, so it doesn't need to be up on the dash. I also found a convenient place to mount the PWM circuitboard.
As mentioned above, I'm not using a manual switch for the fog lights. Instead, they will come on with the running lights. So I tapped into the running light wiring, to activate the fog light relay. In the photo below, you're looking at the electrical plug for the rheostat that controls the brightness of the dash lights. That gray wire on the right comes from the headlight switch. It has power when the running lights or headlights are on. And that's exactly what I want.
In the photo below, the wiring is hooked up to the PWM dimmer. And that finishes the wiring.
The kick panel is reinstalled. Now you can see the dial knob.
And last but not least, the money shot! The fog lights are pretty bright, even with the brightness at 50%. Good thing I installed that dimmer...
Not sure why, but on camera the fog lights look more yellowish. In real life, they're more of an amber color. Which is good. The amber color is more pleasing to my eyes.