I wish to install daytime running lights on my prius. But I can not find an ACC fill in the engine compartment. If a person can help me. I can also go on the power of my 12V outlets in the car, but how to pass my cable from the engine compartment to the cockpit. So simpler if I find an acc cable in the engine compartment. Thank you for your help. Axel of France.
Use a test light in the underhood fuse box to identify fuses that have power only when the car is running. Stay away from fuses for ABS, ECM and high voltage management. Remember that this wire is merely part of the relay's trigger circuit. Another alternative is to pick-up the trigger from high beam or low beam circuits (or both - if both then you will need diodes on each circuit to prevent hi and low beams cross feeding through the trigger circuit). I have included a typical foglight circuit obtained from the following site: https://i0.wp.com/www.accessconnect.com/images/fog_lights.jpg If I was installing this circuit I would connect the green wire (part of the trigger circuit) to: i.) low beam power wire; or ii.) underhood fuse that only has power when car is "ready". If I wired using the "i" alternative, I would eliminate the SPST switch from the circuit as the fog lights would now be effectively controlled by the headlight switch. I hope that helps.
Hey Jimbo: I saw your comment on the daytime running lights (AKA "DRL") and not using the 12V Prius battery. Instead, you suggested that the DRLs be powered by "ready". I am unfamiliar with "ready" under the hood of a Prius. Please tell me more about using "ready" as the source of power and how it differs from 12V power obtained ultimately from the Prius' 12V battery. Many thanks for sharing.
When your Prius is in Ready, the DC to DC converter is supplying about 14 volts to charge the 12 volt battery, so there is no drain on the battery. It is a tiny battery. Starts at 15:00 to 18:00 about the board that includes the A/C inverter and DC to DC Converter.
If you can find a fuse box under the hood, then you have a wide choice of power taps to use. Just look at the lid of the fuse box for guidance. Make sure you tap into the side of the fuse that has no power when the fuse is not inserted. That way your new lights will be protected by the fuse in that circuit (make sure you are not exceeding the power draw with your lights). As for running the DRLs from the 12V (as in ACC mode) or when the car is "READY", I really don't think it matters as long as you are aware that the 12V battery is small and will not hold out long with lights on without the "READY". In fact, it is fully possible to run headlights when the car is off, but you are subject to the same limitation of a very small battery and doing that at your own risk. Do not run the DRLs from your "cigarette lighter" outlets inside the car. It is simply not necessary. You can tap into the same circuit in the fuse box under the hood. I hope that was clear, if not I can take some pictures of my fuse box and annotate them.
I did the exact same thing (see attached image). Ultimately, I was not able to find a switched 12v source under the hood of any kind - every single point I tested was always-on. I ended up tapping the interior fuse for the windshield wipers (high current, only on when READY) and running a wire through the firewall, and they work great. The DRLs are in the lower grill slats on my car. Accompanied by LED headlights, turn signals, and marker lights, they really add to the look of the car. Hopefully the image works. I am not sure how this site handles images.
