New project, DRL mod (3 Viewers)

[dylans]

My 2013 Trail uses the old halogen bulbs for the DRL. Also, the DRL acts as the turn signal. One 1156 bulb, two functions. Years ago I put an ARB bar on and wired the new turn lamps to the factory harness. These cheap Arb turn housings weren't meant to have a DRL halogen in them and I melted them quite a while ago.

I tried changing to LED and got hyper flash. I thought about resistors but they would be constantly running due to the DRL nature. No thanks. I thought about filing down the bar inside of the flasher assembly but nah, im hard pressed to find an LED bulb that's meant for DRL purposes.

It's time to fix this issue.

I put some diode dynamics 1 inch pods on my motorcycle for forward visibility and they have a cool backlight function that's low power, always on, and bright. I recently found that their ss3 pods have this as well in amber. They've got a fog pattern too. My plan is to replace my ARB fog lights, they're not the best anyway, with these and wire the backlight to the DRL.

Easy right, but id like to go a step further and remove the DRL from the turn circuit completely. I wanna give the DRL function from the stock switch to the new fogs and have the turns operate independently like normal.

Looking through the headlight wiring diagram, I see that the DRL comes out of the main body ECU and into the flasher assembly. It's a green wire.

I got into the dash and found the flasher assembly and the green DRL wire. Testing with a multimeter, I found that with the engine running and the harness plugged into the flasher assembly, the green wire reads 71.4 mV with the DRL switched on. Switching them off, the green wire then reads 13.7 V. Multiple tests render the same results.

Unplugging the harness plug from the flasher assembly, and then with the engine on the green DRL wire reads 80 mV with them on and 40 mV with them switched off.

I wanna run this through here, before I order lights, cut and splice anything.

The Green DRL wire can obviously be removed from the flasher assembly. Given its low power, I think id have to use it as a trigger wire on a new relay. Id have to run fused power from the battery (my aux fuse block) to the relay and then out to the backlight wires for the new fogs.

Any input from electrical peoples?

 

[dylans]

I wired up a relay with extra long wires to do some tests.

My first attempt didn’t work out, I had tapped the DRL wire and ran it to 85 on a relay and a 12v source onto 86. I used another fused 12v source from my aux fuse block and ran it to 30. I then ran 87 to the backlight wires. No go.

Looking through the wiring diagrams more, I found that the DRL is powered by the turn/haz fuse and it all made more sense. I used a fuse tap on the turn/haz and ran that to 30 on the relay. I tapped that same wire and ran it to 86. I ran the tapped DRL wire to 85 again and 87 to the lights. It worked! The ss3 backlights were able to be switched on and off with the stock DRL switch. The turn signals/hazards operated independently and normally. Since I was still tapped into the DRL wire though, the ARB turn signals were still getting a DRL signal and were on with the ss3 backlights as well.

I cut the DRL wire under the dash, and spliced the ecu side right into my test relay wire leading to 85. All is functional and the ARB turn signals are no longer attached to the DRL circuit. I tested the DRL function with the new lights in all ways possible and it is totally functional. I also tested the turns and hazard lights in all possible ways with combinations of lights on and off and they are also totally normally functional. Success!

My final step is to make up a nice harness with clean wiring, crimp connectors and adhesive shrink tube, positaps etc.

I’ve got two options for wiring and mounting the relay, under hood with the fuse tap or under dash and tap into the 12v turn/haz wire there. I’d prefer under dash because I’d have shorter wires to deal with and organize minus the power leads to the lights. I’ll also be using a dual output hella relay so each backlight has its own feed. As far as fusing, the ss3 backlight function is only .4 watts and draws 30mA. I believe that tapping the 12v lead for the turn/haz under dash will be fine, as the circuit has a 15A fuse.

I’ve also got new ARB turn signal lamps to go in once I put the weatherpack connectors on.