I don’t like DRLs. So I killed mine!
There’s a safety feature built into new cars these days: Daytime Running Lights (DRL). I don’t like it. I think I have a few good reasons too:
- When pulling into neighborhoods late at night, I’d like to be courteous and turn my headlights off, so as not to shine into the houses.
- The DRL sensor in my car is way too sensitive and turns on when the least bit of shadow covers my cabin (in broad daylight).
When the DRLs turn on, the headlight switch becomes inactive, i.e, you can’t turn the headlights off if you wanted too.
Hence, it was time to disable the feature in my 2003 Toyota Matrix. But I didn’t want to merely snip a wire and be done with it. I would ideally like to be able to revert back to factory condition if I ever wanted to (can’t see that I would), especially if I sold the car in the future.
With the help of some great internet sites and email lists (Matrix email list), I got all the information I needed to proceed. (See references below for specifics)
I bought a Toyota fog light switch (P/N 00550-35976), which fits nicely into an empty bay in the dash. There is usually at least one extra bay available for options.
The pinout of the switch is simple:
Pin 1 – (no terminal)
Pin 2 – switch terminal 1, battery plus
Pin 3 – switch terminal 2
Pin 4 – lamp terminal, battery minus
Pin 5 – (no terminal)
Pin 6 – (no terminal)
There is a built-in resistor of 50 Ohms across pins 3 and 4 of the switch. Apply +12V across those pins and the LED lamp lights up.
For my cabling, I chose a standard AC power cord from a PC, since I needed three wires and it already had a nice thick plastic jacket.
Next was the DRL wiring. Before starting that, you have to disconnect the battery. Be careful when reconnecting it though! I had a lot of trouble with my alarm system activating, thus turning on the horn alarm, until it figured out that I wasn’t trying to break in. Thus, I also recommend disconnecting the horn until all that is settled.
See below for an accurate pinout of the DRL connector, looking into the back end of the connector (not mating end).
According to the TSB for this procedure, pin 12 becomes +12V when the DRL system engages (low ambient light detected). Thus, the first big step was to locate and cut pin 12. It’s a Red/White wire right next to the larger gauged White/Black (pin 2) wire.
I wanted to wire my switch such that the LED was off when I disengaged the DRL system. With the switch on, the LED would be on and the DRL would be engaged. Therefore, pin 2 of the switch should be wired to the DRL supply wire (Red/White). Pin 3 of the switch should be wired to pin 12 of the DRL connector (the other side of the wire just cut). Finally pin 4 should be wired to chassis ground. For this, I soldered a spade lug and placed it under the washer and bolt holding the DRL assembly to the chassis.
On the other end, I soldered on spade terminals to the cable and connected them to the appropriate pins of the switch.
Finally, the switch fits very nicely into place in the dash switch panel. Works like a champ!
- http://dalenet.com/matrixvibe (same mod, different switch)
- Yahoo Matrix email list