Disable headlight DRLs, relocate them, and KEEP auto lights!
This tutorial will accomplish three things and is fully and EASILY reversible:
1. Disable your headlights operating as DRLs.
2. Relocate your DRLs to the fog lights, or a relay to an auxiliary light.
3. MAINTAIN factory function of auto lights.
This mod was done on a 2004 Pontiac Vibe, and I cannot promise that it will transfer to Vibe GT, Matrix, or 2nd Gens. As with anything on this site, or most other forums, neither I, nor this website take any responsibility for legal or functional problems that may occur as a result of this modification. I also am not an expert and will be using basic terms, explaining things the way I understand them, but may not be technically correct. Thanks to “calata” and “tribalman” for their previous efforts to originate this mod.
The fault to this mod is that you will lose the function “flash to pass” of your high beams when the headlights are off. This function will work when the headlights are on. You will also lose the ability to turn on only your parking lights or “running lights”, as the headlights will be wired to turn on as the tail lights turn on.
There are three basic operations that make up this mod:
1. Cut the wire that sends the signal to the headlights to come on, including to come on as DRLs.
2. Send the signal for the DRL to illuminate to the fog lights (or an auxiliary light).
3. Send the signal for the tail lights to the headlights so they turn on when the taillights come on.
Tools and materials you will need:
Flathead screwdriver, preferably a long, narrow one.
Phillips #2 screwdriver (#2 is the most common size).
Wire snips / trimmers / strippers / crimpers.
About a foot of insulated, stranded wire, I used 16 gauge, but 18 or 20 would be acceptable.
Insulated spade connectors, I used 3 each of mid-size male, mid-size female, small-size male, and small-size female. The “small-size” (usually red or purple, for 22-18 gauge wire) will need to accept one 20-gauge stranded wire each, and the “mid-size” (usually blue, for 16-14 gauge wire) will need to accept two wires each of whatever gauge you chose to use. This should make sense later on when we build some wire splitters.
Locate the DRL module under the dash. The best way I found to do this is by laying on your back, with your hips outside the car and your upper back on the driver’s floor mat. As you maneuver backwards into the footwell, place your right elbow back into the dead pedal area (where your left foot would rest) so that you can reach your right hand up into the dash easier. Here is a picture of the module, which can also be identified by pushing it to the side and seeing the label “RELAY ASSY. RUNNING LIGHT”. Unplug the connector by pressing on the small tab in the center of the right side of the connector and pulling on the harness. Go ahead and get back into a normal seating position in the driver’s seat.
The next step is to remove the instrument cluster. Adjust your steering wheel to the lowest position. Pull the black/chrome bezel off the dashboard, usually the top will release first and then the lower edge will release. It does take a bit of force if it has not been removed before. Set the bezel aside. You will reveal the instrument cluster, with a single Phillips head screw at the top center that needs to be removed.
Once the screw is removed, there are two metal tabs at the bottom you must release. Take a small flathead screwdriver and press the metal tab back while gently lifting upward on the side of the closer you are working on. When re-installing the cluster you will simply press the cluster into these tabs. You will hear a ‘click’ sound when they are correctly inserted.
I found removing the instrument cluster was easiest by pulling the right side of the cluster out of the dashboard first, and rotating the cluster so the left end was inside the dash, and the right end was resting on the steering column. You can then reach your hand into the dashboard and release the single harness connector from the cluster. This harness also has a couple wires that head off to the left, make sure not to catch the harness or cluster on these wires. Leave them alone and don’t accidentally pull them out.
Once you release the harness you can remove the cluster and set it aside. You will be able to reach your hand into the dashboard and locate the harness you unplugged from the DRL module in the back right corner of the cavity, behind the metal dashboard brace. You will find it easier to remove the electrical tape and maneuver the wires to give you the most length to work with. Pull the connector towards you, making sure not to catch the wires on anything, and keeping them neat to keep them from getting crimped (think of when you pull on a garden hose without untangling it, it’s not good for the wiring).
Looking at the connector from “above” or the side that the wires are coming out, you will see two large wires on the left, and 18 small wires on the right. From left to right, the two large wires are #1 and 2, the front row of small wires are #3-11, and the back row of wires are #12-20. The wires you will deal with are #4 (green w/ orange stripe), #6 (red w/ yellow stripe), and #14 (green w/ black stripe). When identifying the wires, I found it helpful to notice that the “green” wires are an evergreen shade of green, think of the shade of green used at Christmas time. Also available is a wiring diagram. Note that the #9 wire is missing from the diagram, and on my vehicle, there was no #17 wire in the connector. Note that in the picture, when viewing the back of the connectors, the #12-20 wires are shown in reverse order; #20 is on the far left, and #12 is on the right, just next to the two large wires.
Cut the following wires about 2-3 inches from the connector that previously went into the DRL module. This will give you enough wire to add connectors to both ends comfortably, without being too cramped inside the dashboard. The basic ideas behind this mod are as follows, and this is where I will oversimplify a few things for ease of understanding, and by no means should these statements be used to justify other wiring projects:
By cutting the #6 wire (red w/ yellow stripe), you sever the wire that tells the headlights to come on as DRLs, this is wire #6 (red w/ yellow stripe). The end of #6 that goes into the connector (the short end) carries the signal for the DRLs to turn on, and the end of #6 that goes back into the dashboard leads to the headlights. You could stop here, but your headlights would not work. They don’t work without the DRL module. Cars are wired in a way that is economical in cost and engineers think in a way more complicated than “turning on the headlight switch gives power directly to the light bulbs”.
To keep function of the headlights, we need to tell the headlights to turn on when we want them to. Put simply, if we are using the taillights, we want the headlights to also turn on. To accomplish this, we are going to connect the long end of #6, that leads to the headlights, to the #14 wire (green w/ black stripe) which goes to the taillight relay and tells the taillights to turn on. This means when the taillights come on, the headlights will come on. This is also why you will lost the ability to drive with only your parking lights or “running lights” on. You could again stop here, simply wrapping some electrical tape around the loose end of the #6 wire. This would theoretically disable your DRL, cause your headlights to turn on with the taillights (and with auto lights), and you’re done… but why not make the fog lights your new DRLs for safety? If not your fogs, then any other light you like!
*** If you do not want your fog lights to operate as DRLs, avoid cutting the #4 wire. Avoid any modification to the #4 wire. You will also only need one wire splitter, with a single MALE spade connector, and two FEMALE spade connectors.
*** If you would like your fog lights to operate as DRLs, continue with this write-up as it is written.
*** If you would like to add an auxiliary DRL, connect the short end (that comes from the connector) of the #6 wire to a relay that powers your auxiliary light.
*** If you would like to leave your DRLs completely disabled, skip the next paragraph.
The short end (that comes from the connector) of the #6 wire carries the signal for the DRLs to be on. Connecting this wire to the #4 wire (green w/ orange stripe) which leads to the fog lights, will cause the fog lights to turn on whenever your DRLs would have come on. This is possible because the fog lights previously only worked when the headlights were fully turned on, at which point the DRL turned off. You will now have the choice to use your fog light switch to manually disable the fog lights (even as DRLs) and turn them on at any time the car is running. They will turn off when the car is turned off.
Now that you know what’s happening, go ahead and cut the #4 (green w/ orange stripe), #6 (red w/ yellow stripe), and #14 (green w/ black stripe). Strip the ends about 1/4 inch to expose the wires. Terminate the short ends of the wires (going into the connector) with your small-size MALE spade connectors. Terminate the long ends of the wires (going back into the dash) with your small-size FEMALE spade connectors. It isn’t terribly important which set of wires have male connectors vs female connectors, but having all male connectors on the short / connector end, and all female connectors on the long / dash end, will make it simple to reverse this mod. Simply unplug the wire splitters you build in the next step and connect your matching factory wires to each other.
Now that you have everything on the car side sorted out, we will step aside and build some wire splitters.
Cut your own wire (mine was 16 gauge, but you may use 18 or 20 gauge) into four 2-3 inch pieces, and strip both ends of each one. Twist two of the wires’ ends together to create a “Y”. Do this with the remaining two wires. Using your mid-size spade connectors, connect a FEMALE spade connector to one of the bundled wire pairs (the end you twisted together). Connect MALE connectors to the separate ends of those two wires. You should now have a “Y”-shaped wire splitter with a single FEMALE connector at the base of the “Y”, and two MALE connectors, one at each end of the “Y”. This is the wire splitter you should build even if you do not want to use your fog lights as DRLs. To make a second wire splitter, do the opposite, so you a have a “Y” shaped wire splitter with a single MALE connector, and two FEMALE connectors. This one will send the power to your fog lights.
Take the first wire splitter you built, and plug the SINGLE FEMALE end into the male end of the #14 wire (green w/ black stripe) that comes out of the connector. Plug the two male ends into the female ends of the #14 wire (green w/ black stripe) and #6 wire (red w/ yellow stripe) that come from inside the dashboard.
Take the second wire splitter you built, and plug the SINGLE MALE end into the female end of the #4 wire (green w/ orange stripe) that comes from inside the dashboard. Plug the two female ends into the male ends of the #4 wire (green w/ orange stripe) and #6 wire (red w/ yellow stripe) that come out of the connector.
Test your wiring before you put everything together. Make sure that everything operates how you expect it to. You shouldn’t need to use any wire loom or zip ties, as the wires are short enough, and out of the way, that they won’t interfere with any moving parts such as the steering column. Gently push the DRL module connector and your new connections back into the lower right corner of the dash. You might be able to get the connector plugged back into the DRL module from here, but personally I found it easier to just get back down on the floor and do it from below. Re-install your instrument cluster and bezel. You did it! Congratulations!
Video demonstration: https://www.youtube.com/watch?v=_arYaEW89B4