HID's and Daytime Running Lights

[rage2]

Hey guys, new here, just picked up my Yaris this weekend and installing mods all week.

I noticed that a lot of people have problems with DRL and HID's because low beam voltage is different for DRL vs normal low beam. I measured my canadian car and got 10V for DRL and 12V for normal low beam.

So I'm building a small relay that basically uses the lowbeam 10V/12V for control, and feeding 12V back to the harness. This would make DRL operation as well as normal low beam operation 12V to the bulb/harness/HID, etc. We're not allowed to disable DRL's in Canada, so I figured this is the best way to go to have HID as well as DRL.

Wondering if anyone's done the same thing?

[Chris07LB]

Most us guys in the U.S., have just disabled them using my DIY How To.

I for one hate the look of DRLs on any car, and as long as they are not "needed" by law to be hooked up, I'll keep them disabled.

You may have a good solution for the Northern folks who need to have them working.

Keep us posted.

[rage2]

Well I guess I don't have to do this anymore, I called a local shop, and their HID kits has the exact circuit built in already, so it's DRL friendly.

[Chris07LB]

Originally Posted by rage2

Well I guess I don't have to do this anymore, I called a local shop, and their HID kits has the exact circuit built in already, so it's DRL friendly.

Id like to know more on this... I have had lots of HID kits in the past, and never did one not cause the DRLs to go wacky. You know how the DRLs work with Halogens, so no need to explain.

[IllusionX]

oh, so it's really 10v for DRL and 12v for low beam... then with a relay switch, i can send the DRL to the fog lights easily.

now that's something very interesting.. thanks

[rage2]

Alright, so here's the wiring diagram of where to put the relay. Turns out that the lights are ground switched, which is even better, only need 1 part and some wires to do this.

So the plug to the bulb has 3 wires:

Green - Ground HighBeam
Blue - Ground LowBeam
Black - 12V constant

When the DRL is active, Black and Blue measures 10V (Canada, not sure about US)

When the lights are on, Black and Blue measures 12V.

When the high beams are on, Black and Green measures 12V.

Here's how you tap into the line... I'd tap this at the HID harness so you don't cut stock wiring.



This would make it so when DRL is on, Black and Blue will measure 12V since it's switching from chassis ground. No need for additional fuse since the 12V from the plug is already fuse protected.

The HID kit that I got from a local shop says they have this in the harness already, so it works fine. If not, it's a simple hack to get it working nicely.

[Violin]

Have you tested this and found it to work?

[Black Yaris]

why not disable the DRL? make life a lot easier

[rage2]

Originally Posted by Violin

Have you tested this and found it to work?

I just picked up a relay to test the circuit tonight after work, but I'm confident that it will work fine, assuming I still remember all my high school electronics classes haha. I'm told the HID kit that I got already has this, so it's not needed, but I wanted to see if it works so others can do it themselves. I'll update with test results tonight.

Originally Posted by Black Yaris

why not disable the DRL? make life a lot easier

Cuz I'm from Canada, DRL's are mandatory here.

[rage2]

OK I tested the circuit, and it works fine. My HID kit isn't in yet, but my left halogen runs full 12V power on lowbeam and DRL. It's a 10 minute soldering and heatshrink/electrical tape job if you want to hack your HID harness.

[Violin]

Cool! Good work - thanks .

[marcus]

hey wouldnt that make ur hid ur drl as well....

Originally Posted by rage2

Alright, so here's the wiring diagram of where to put the relay. Turns out that the lights are ground switched, which is even better, only need 1 part and some wires to do this.

So the plug to the bulb has 3 wires:

Green - Ground HighBeam
Blue - Ground LowBeam
Black - 12V constant

When the DRL is active, Black and Blue measures 10V (Canada, not sure about US)

When the lights are on, Black and Blue measures 12V.

When the high beams are on, Black and Green measures 12V.

Here's how you tap into the line... I'd tap this at the HID harness so you don't cut stock wiring.



This would make it so when DRL is on, Black and Blue will measure 12V since it's switching from chassis ground. No need for additional fuse since the 12V from the plug is already fuse protected.

The HID kit that I got from a local shop says they have this in the harness already, so it works fine. If not, it's a simple hack to get it working nicely.

[rage2]

Yep, DRL's are HID, same as low beam.

As posted in the other thread, you have a choice of relays to use for this circuit.

10V activation - DRL and low beam same thing, activates HID.
12V activation - DRL never comes on, low beam activates HID.

[marcus]

ok i found a way to keep fog lights , drl and run hid WITH high beam still!!!!!!!!!!!!!! so simple i really dont know why i didnt think of this sooner!!

Originally Posted by rage2

Yep, DRL's are HID, same as low beam.

As posted in the other thread, you have a choice of relays to use for this circuit.

10V activation - DRL and low beam same thing, activates HID.
12V activation - DRL never comes on, low beam activates HID.

[rage2]

What method did you end up using?

[marcus]

ok for canadian models...with fogs.. ...to keep drl,fogs,hid bi-xenon with high beam.. here it is u just need to cut 2 wires...headlight should have 3 wires, ground, low,and high. cut the low beam wire.. then cut the positive wire on the fogs..interconnect them..therefore when the car is on ur fogs is running on 10v (drl). once the headlight switch is turned on that should activate ur hid ( which was interconnected w/ the fogs.which is actually the fog light. high beam is still ur high beam.....
so 2 wire interconnected...drl=fogs=lowbeam, fog switch =(hid)low, then high beam remain as is.....no relay needed may need to supply a lower amp for the fogs..coz its running amp from the headlight..and fog amp should be sufficient to run the hid bi xenon.

[rage2]

Originally Posted by marcus

ok for canadian models...with fogs.. ...to keep drl,fogs,hid bi-xenon with high beam.. here it is u just need to cut 2 wires...headlight should have 3 wires, ground, low,and high. cut the low beam wire.. then cut the positive wire on the fogs..interconnect them..therefore when the car is on ur fogs is running on 10v (drl). once the headlight switch is turned on that should activate ur hid ( which was interconnected w/ the fogs.which is actually the fog light. high beam is still ur high beam.....
so 2 wire interconnected...drl=fogs=lowbeam, fog switch =(hid)low, then high beam remain as is.....no relay needed may need to supply a lower amp for the fogs..coz its running amp from the headlight..and fog amp should be sufficient to run the hid bi xenon.

The low beam wire is actually a ground. Connecting that to the fog's positive would kinda blow shit up. The 3 wires on the headlight plug is actually:

12V
LowBeam Ground
HighBeam Ground

I'm not sure how the foglight circuit is setup, so I can't really tell you how to set it up your way properly.

[marcus]

you most definetely dont want to connect negative to positive..you gonna short ur yaris there well if those are really ground then it has power wire.. switch power wire from headlight to fog light power wire it should work..there is no way it wont work..but even if those are the ground wire and it should still work switch headlight ground to fog light ground...