2012 GEN 3 Install Fog light Switch to keep DRL to Stay ON

It's pretty easy but you're going to have to run wires through the firewall between the engine and passenger compartments. Look at the installation instructions for the oem foglights here in post #1, specifically the part about running a wire through the rubber grommet by the brake pedal.

2010 Prius OEM-quality Fog Light Kit Now Available! | PriusChat

If you think you can do this then we can proceed. If you don't feel comfortable doing that, then you will have to settle for the jumpered relay with the always on option.

 

1) You would need the DRL switch.

Brand New LED DRL Daytime Running Light Special Switch Control for Toyota Lexus | eBay

2) Two fuse taps. One to get +12v when in Ready Mode from your passenger compartment fuse box, and the other to tap the fuse in the engine fuse box to supply power to the DRL relay terminal.

2 Add A Circuit Standard ATM APS Low Profile Blade Style Fuse Holder Tap 5 Amp | eBay

3) At least 16 feet of 18 awg stranded copper wire.
4) 2 ft of 14 awg wire.
5) Assorted crimp connectors and electrical tape.
6) Extra 10 amp low profile mini ATM fuses (2).
7) A relay to control the power to the DRLs and to take the load off the DRL switch. Something like this:

12V Volt 5 Pin 30 40A Amp Automotive SPDT Relay Interlocking Socket Wire Harness | eBay

8) Optional: Split wire loom, makes the wires more tidy, especially in the engine compartment.

10 ft 1 4" inch Black Split Loom Wire Hose Cover Conduit Poly Tube Tubing | eBay


Measure out about 16 feet of the 18 gauge wire, fold the wire in half at the midpoint. Follow the instructions in the oem foglight install guide to push the 18 gauge wire through the firewall rubber grommet (two wires because they're folded over). Pull the wires through the grommet so that one end is near the passenger compartment fuse box near the driver's side footwell, the other end of the wires needs to be by the engine fuse box. At this point, you can cut the wire end where it was folded over on itself to separate it into two wires.

Refer to the DRL always on mod instructions where the jumper is placed between the fuse and the DRL relay in the engine fuse box. You are going to install one fuse tap device into the appropriate fuse location in the engine compartment fuse box and connect the wire coming out of the low profile mini ATM fuse tap to a 14 gauge wire, connect this to one of the wires on the normally open circuit of your relay (terminal 30 on relay). The other wire on the normally open circuit of the relay (terminal 87) will be connected to the wire that is plugged into the terminal exposed when the DRL relay was removed from the fuse box, use 14 gauge wire for this as well. The ends of the 18 gauge wire will be connected to the coil wires of the relay, terminal 85 and 86 separately. It doesn't matter which wire is connected to which wire. The wire going to terminal 87a on the relay will be unused, make sure it is insulated against short circuits.

In the passenger compartment, install a fuse tap device into an appropriate fuse location that supplies +12v when in Ready Mode (I use a Seat Heater fuse location (red 10 amp fuse) for +12v when in Ready Mode for my mods.

Install the DRL switch into the dashboard (refer to the oem foglight installation instructions). Now, you have to locate which wire on the DRL switch is used for the illumination light on the switch. Connect this wire, along with one of the 18 gauge wires pulled through the firewall, and one of the wires on the DRL switched circuit, to the wire from the fuse tap device. Connect the end of the second 18 gauge wire to the second free wire from the DRL switch that controls the switched circuit. There should now be only one free wire from the DRL switch, the black ground wire. Connect the ground wire to a ring terminal and put it under a bolt or screw that is attached to a metal subdash frame. Put everything back together.

If everything is connected properly, the letters "DRL" on the switch will illuminate when the car is in Ready Mode. The green indicator light on the switch will illuminate when the switch is pressed in (On), and turn off when the switch is disengaged (Off). Additionally, you should have control over your DRL lights.

 

Yes, and make sure the relay is rated for DC use.

 

Love to do this. Update us with pictures thanks.

 

Would you mind pointing me to this info? The search feature on this site is convoluted at best.

Thank you.

 

^ I agree. You can type the precise thread title and it STILL won't find it, half the time. Just use google to search, and commence the search string with "priuschat". Google actually perpetuates lousy website search engines, they don't need to work, everyone just gives in and googles.

 

Post #46, on page 3 here:

How can I mod the DRL to have it on at all time? (for 2013 models) | Page 3 | PriusChat

Sorry, I don't know how to link to a specific post within the thread.

And the install instructions for the oem foglights is here in the first post.

2010 Prius OEM-quality Fog Light Kit Now Available! | PriusChat

Where, specifically, it mentions where the rubber grommet is to push wires through the firewall is.

 

Reading Xlideriders' shopping list in post #4, you guys are going through a lot, to install something that's not mandatory, and going at it in the most difficult way. It's largely for the look I guess?

In Canada, turn the car on, release the parking brake: the high beams come on at reduced brightness. That's the DRL. Turn headlights on, DRL goes off.

 

Yeah, I actually built my own highbeam DRL module to get that functionality on my 2011, which is the model year prior to the LED DRLs coming from the factory. It was pretty complex, 3 relays, diodes, etc. Cost me over $200 including all the trial and error materials, etc. Then I found a solid state module on eBay that did the same thing, and installed that. Link is in my signature below.

My avatar pic is a full sun shot with the highbeam DRLs on.

 

Thank you very much.

On the post where it shows the post number, click on it. A link will pop up. Paste that link and it will link you straight to the post number.

Example: In your post at the bottom right where it says "#10". Click on that and paste the link: 2012 GEN 3 Install Fog light Switch to keep DRL to Stay ON