I surprised my wife with a new (to us) Honda Pilot. It has been a great vehicle, but it was missing a fairly simple feature that her base model 1999 Chevrolet had. The omission of automatic / day time running lights seemed odd for a high-trim Honda. I looked around for solutions and came up with nothing that was reasonably priced or that I was willing to do. My solution turned out to be adding a set of TIP41C transistors (two) in the steering column in series with the existing wiring/switch so that the switch may be left in the on position and the lights will turn on and off with the ignition, and you still have control to turn the parking/head lights on and off with the switch on the stalk should you so desire. The transistors are rated for 6A, and with the switch in the signal stalk only controlling ground to the relays under the hood, I expect the transistors will not need a heatsink.
The TIP41C transistors have three pins:
- Base – connects to the positive run lead coming off of the ignition, serves as the “signal” input that connects the Emitter and the Collector “together”
- Emitter – connects to the lead coming from the turn signal stalk harness
- Collector – connects to the lead going into the dash
The lights are controlled in two stages: parking lights and headlights.
The parking/headlight switch in the stalk works by connecting the red/yellow and blue/black wire to ground (larger black wire in the harness). In most of my testing the parking lights must be on first for the headlights to turn on.
In the steering column there is one wire to tap into, and two wires to cut. For the cuts, be sure to leave plenty of room to solder or connect some sort of a splice to the wires.
Tap: large black wire with yellow stripe coming off of the back of the ignition. This will connect to the Base pin on both transistors, and acts as the signal that will turn the headlights on and off with the ignition.
Cut: Red wire with yellow stripe – controls parking lights (front and rear) and the interior dash light.
Cut: Blue wire with black stripe – this controls the head lights.
Connect the Emitter pin to the blue/black wire lead coming off of the wire harness.
Connect the Collector pin to the blue/black wire lead going into the dash.
Connect the Emitter pin to the red/yellow wire lead coming off of the wire harness.
Connect the Collector pin to the red/yellow wire lead going into the dash.
I would recommend using a voltmeter to test your ignition voltage and alligator clips to test that you have the Emitter/Collector hooked up correctly before soldering your connections into the wiring harness. This saved me the hassle of doing and redoing the connections and ensured that everything worked electrically before making the connections in a more durable manner. In all the project could be done in about 30-45 minutes by someone taking their time, and less than 30 minutes for someone experienced with automotive wiring and electronics.
I performed this project on a 2003 Honda Pilot EX-L . Looking at my Haynes manual for the vehicle and it should apply to the 2003 to 2008 Honda Pilot and possibly the 2006 to 2014 Honda Ridgeline. If you have the same color wires in your harness, you can test connecting the red/yellow to ground to see if your parking lights turn on, and then connect the blue black to ground to see if your headlights turn on. If they do then you should be able use this guide to wire in auto headlights.
Disclaimer: Be sure you know what you are doing and that you are comfortable with the changes outlined above before starting this project. The wiring changes should be easy to put back to the way they were before should something not work, but incorrect wiring could result in permanent damage to the relays or other sensitive electronics in your vehicle. I am not responsible for any damage you do to your own vehicle.
If you found this helpful please leave a comment below. I like to know that my tribulations have helped someone 🙂