2013-2015 LX570 LED DRL voltage?

[2014 LEX 570 GA]

Linking this thread from Lighting forum over here in hopes of getting more traffic, particularly from the electrical engineers in the house.

Post in thread 'LX 570 - SS3 Fog Lights (w install)'
LX 570 - SS3 Fog Lights (w install) - https://forum.ih8mud.com/threads/lx-570-ss3-fog-lights-w-install.1228101/post-14795601


Trying to tap the LED DRL wire to power my Diode Dynamics SS3 fogs so they run at a low voltage whenever the DRLs are on.

Unsure of which wire is the DRL but used a voltmeter to test current. Not sure if the DRL is identifiable based on current?

PS, I am electrically challenged.

 

[bloc]

You sure you used the multimeter to check current? Did you mean voltage?

I doubt the DRL circuit is designed with anywhere near enough current (aka amps or watts, different from volts but also important) to run those ss3s. Meaning even if you find the appropriate wire, it’ll probably just pop the relevant fuse repeatedly.

 

[2014 LEX 570 GA]

You sure you used the multimeter to check current? Did you mean voltage?

Like I said - I am electrically challenged.

This version of the SS3s are designed with a backlight to run simultaneously with the DRLs. Has been done on other Toyotas (Tacoma, Tundra, GX) with no issues.

 

[Leaky2014]

Linking this thread from Lighting forum over here in hopes of getting more traffic, particularly from the electrical engineers in the house.

Post in thread 'LX 570 - SS3 Fog Lights (w install)'
LX 570 - SS3 Fog Lights (w install) - https://forum.ih8mud.com/threads/lx-570-ss3-fog-lights-w-install.1228101/post-14795601


Trying to tap the LED DRL wire to power my Diode Dynamics SS3 fogs so they run at a low voltage whenever the DRLs are on.

Unsure of which wire is the DRL but used a voltmeter to test current. Not sure if the DRL is identifiable based on current?

PS, I am electrically challenged.

Look into using a relay.

 

[bloc]

Like I said - I am electrically challenged.

This version of the SS3s are designed with a backlight to run simultaneously with the DRLs. Has been done on other Toyotas (Tacoma, Tundra, GX) with no issues.

Ahh ok. That's a different story.

This is the relevant part of the electrical wiring diagram (EWD) for a 2014 LX

First off.. toyota technically has two DRL systems on your rig. There is the LED strip, but also a step-down resistor (DRL MOD relay in the diagram) that provides less than full power to illuminate the High beam bulbs as the real DRL. At least on my 2013 Cruiser i can disable this in the nav system options, this may be the default on LX's, not sure. But all of that is in the diagram above.

You also can clearly see a red wire going to the three arrow sign.. on wiring diagrams that's the symbol for a light emitting diode. That's what you are looking for.

The thing that bothers me about this diagram is it is odd for toyota to have different wiring color schemes per side.. or swapped anyway. If you look closely the right headlight low beam is a black wire, and but that circuit is red on the left. Swap the colors for the high beam. Toyota does occasionally make mistakes on their EWDs.. and I did look at the 2013, it is different on these circuits. either way we can work around this since those aren't the wires you need.

Looks like the one you want is the DRL +12v red wire on each side. This should be on pin 5. if you look closely at your connector on the back where the rubber gasket is next to each pin well will be a very, very small number molded into the connector. This is the pin number. it should correspond to the numbers in the EWD attached to this post.

From your other thread, I see no pin numbers but a thick red wire and a thin one. It stands to reason the thick wire is for the high beam, but double check this with your meter. If that lines up, and as mentioned above should be a different color on the other side, check that pin number and figure out what's going on to find pin 5 and the wire you need.

Leaky's advice to use a relay is solid. Technically the wires you are looking for are already controlled by a relay, however without knowing how much current the DRL portion of the new fogs will draw, you are taking a risk. A properly set up relay system will eliminate this risk. You could easily run both new DRLs off one relay/trigger wire.

 

[2014 LEX 570 GA]

Ahh ok. That's a different story.

This is the relevant part of the electrical wiring diagram (EWD) for a 2014 LX

View attachment 3225354

First off.. toyota technically has two DRL systems on your rig. There is the LED strip, but also a step-down resistor (DRL MOD relay in the diagram) that provides less than full power to illuminate the High beam bulbs as the real DRL. At least on my 2013 Cruiser i can disable this in the nav system options, this may be the default on LX's, not sure. But all of that is in the diagram above.

You also can clearly see a red wire going to the three arrow sign.. on wiring diagrams that's the symbol for a light emitting diode. That's what you are looking for.

The thing that bothers me about this diagram is it is odd for toyota to have different wiring color schemes per side.. or swapped anyway. If you look closely the right headlight low beam is a black wire, and but that circuit is red on the left. Swap the colors for the high beam. Toyota does occasionally make mistakes on their EWDs.. and I did look at the 2013, it is different on these circuits. either way we can work around this since those aren't the wires you need.

Looks like the one you want is the DRL +12v red wire on each side. This should be on pin 5. if you look closely at your connector on the back where the rubber gasket is next to each pin well will be a very, very small number molded into the connector. This is the pin number. it should correspond to the numbers in the EWD attached to this post.

From your other thread, I see no pin numbers but a thick red wire and a thin one. It stands to reason the thick wire is for the high beam, but double check this with your meter. If that lines up, and as mentioned above should be a different color on the other side, check that pin number and figure out what's going on to find pin 5 and the wire you need.

Leaky's advice to use a relay is solid. Technically the wires you are looking for are already controlled by a relay, however without knowing how much current the DRL portion of the new fogs will draw, you are taking a risk. A properly set up relay system will eliminate this risk. You could easily run both new DRLs off one relay/trigger wire.

Thanks. This is helpful. I am elbow deep in it now.

Took another look at it and do see the very small numbers.

Your are right in that the wires do not correspond between driver and passenger.


Driver:

Passenger:

I need to re-read your post above and break out the meter again to see if I understand. Still getting the fogs mocked up and Group 31 battery installed.

 

[bloc]

To further narrow things down this diagram shows connector locations in the engine bay. The above EWD has "A40" or "A41" etc on individual parts, that corresponds to locations on the following image. Should help you narrow down which pin and wire goes to which connector.

 

[2014 LEX 570 GA]

Thanks @bloc for the assist with the diagrams. The headlight harness does indeed matchup. High beams are position 3 and DRLs are position 5 on both sides.

Finally got this wired up. Still need to aim the fogs and then zip tie/electrical tape everything away neatly, but below is what she looks like with the DRLs and the fog backlighting. I am happy with results. Please excuse my filthy truck. She’s not an Instagram model and needs some spring cleaning.

 

[bloc]

Nice! I wish cruisers had drop-in fog options like the LX does.

If you want a more secure and watertight splice, they are out there, but I haven’t specifically researched them yet to give you some brand names. You aren’t at risk of a short or anything, but the splice you used can allow water into the copper wires of the harness.

Glad I could help with the diagrams

 

[2014 LEX 570 GA]

Nice! I wish cruisers had drop-in fog options like the LX does.

If you want a more secure and watertight splice, they are out there, but I haven’t specifically researched them yet to give you some brand names. You aren’t at risk of a short or anything, but the splice you used can allow water into the copper wires of the harness.

Glad I could help with the diagrams

Yep the splice is not the most sophisticated way to do this, but path of least resistance for me.

I went wild with electrical tape once I was finished, so unless there is standing water in the engine bay up to the headlights I think it should be fine. And if that happens the probably will have bigger problems.

 

[Source Hydrographics]

Anyone happen to know which wire to tap into on a 2009 lx570? I have a black wire at pin 5 that does not work. It only gets 8.4 bolts running. I haven't gotten the service manual yet but found the attached diagram that is rather confusing as it seems to include multiple years. Thanks!

 

[binhsterbinh]

Yep the splice is not the most sophisticated way to do this, but path of least resistance for me.

I went wild with electrical tape once I was finished, so unless there is standing water in the engine bay up to the headlights I think it should be fine. And if that happens the probably will have bigger problems.

Did you run this Pin #5 wire directly back to the DRL wire of the SS3? Or did you run it to a Relay in between?
I'm presuming you had run it direct as you tapped both headlights, but just wanted to clarify. Thanks.

 

[2014 LEX 570 GA]

Did you run this Pin #5 wire directly back to the DRL wire of the SS3? Or did you run it to a Relay in between?
I'm presuming you had run it direct as you tapped both headlights, but just wanted to clarify. Thanks.

No delay. I am electrically challenged and this is most technical job I have done thus far, so would not recommend you follow my path. I need to revisit and better waterproof mine.

 

[binhsterbinh]

No delay. I am electrically challenged and this is most technical job I have done thus far, so would not recommend you follow my path. I need to revisit and better waterproof mine.

Thanks.
I followed your path but used a Posi Tap instead and just brushed some liquid electrical tape goop into the connector before threading the conductor pin into the factory DRL wire to prevent corrosion.

I tapped into just the passenger side headlight harness and plugged that into the passenger fog lamp backlighting wire. Then I ran the driver side backlighting wire over to the passenger side and did a 2nd Posi Tap into the passenger side backlighting wire. I did have to lengthen this lead though another 12-14” in order to reach the passenger side using solder and adhesive heat shrinking tube to water seal. The wire through the bumper was then zip tied to an existing wire harness in the bumper.

The reason I chose the alternative route was to avoid having to tap into both factory driver + passenger side headlights wire harnesses.

We probably should have added like a 1A inline fuse I suppose, but the risk is relatively low as that backlighting draws only a few watts of power. I installed DD Elite Series in my case and the backlighting is just enough to make the housing glow yellow during the day and by no means bright at all.