Aux Wiring Question. (1 Viewer)

[milesc3]

I'm confident I can fix this, just need a little help. My 2020 HE came from the dealership across the country and I had undercarriage ditch lights installed with a a switch installed by the card holder and by the headlight cleaner button. When that button is "off" (not pressed in) the undercarriage lights are supposed to operate with the "door" function, ie lights on when doors open off when doors closed. That part works fine except when the car is running and I am driving. The lights stay on all the time even though the interior cabin (door) lights are off. Basically it works fine until the engine is running, then it stays on all the time. Anyone point me in the right direction? Here is a video link: 2020 Land Cruiser video.mov - https://ln5.sync.com/dl/d176f7800#4th57d7x-fgzx5x5d-hhf4ucmt-npjc7gsw

 

[prharper]

Check out this thread.
Post in thread 'Anyone tap into DOME light for rock lights in 2017 LC?'
Anyone tap into DOME light for rock lights in 2017 LC? - https://forum.ih8mud.com/threads/anyone-tap-into-dome-light-for-rock-lights-in-2017-lc.1185344/post-12978304

 

[NikP]

It appears they hooked the lights to a keyed power source and not one of the interior light circuits. Or, if the circuit was wired with a two-pole relay, they may have connected the relay coils to the wrong contact and instead of being normally off it's normally on.

 

[100kiwi]

Check out this thread.
Post in thread 'Anyone tap into DOME light for rock lights in 2017 LC?'
Anyone tap into DOME light for rock lights in 2017 LC? - https://forum.ih8mud.com/threads/anyone-tap-into-dome-light-for-rock-lights-in-2017-lc.1185344/post-12978304

Yep, use a solid state relay so they fade in and out like the door lights.

https://a.co/d/dBrYH4N

 

[nimitz]

It’s also possible a tiny amount of power is getting into the circuit and it’s enough to light the LEDS. My buddy has this on his GX

 

[milesc3]

Check out this thread.
Post in thread 'Anyone tap into DOME light for rock lights in 2017 LC?'
Anyone tap into DOME light for rock lights in 2017 LC? - https://forum.ih8mud.com/threads/anyone-tap-into-dome-light-for-rock-lights-in-2017-lc.1185344/post-12978304

thank you!

 

[milesc3]

To recap: There is no issue when the ignition is off. Everything works as it should. Comes on and goes off with dome lights/door open and the override switch works. The problem is when the ignition is one the rock lights are on regardless of anything else. Door switch off/on, override switch off/on, doesn’t matter. If the ignition is on the rock lights are on.


I’ve got the dash apart with the relay accessible. I see the white and black wires coming in from the lights (each side) .


Looks like 2 blacks from lights (1 from each side) go to ground.


RELAY:

Terminal 1 top left: Two whites from lights (load) and a third from switchbank goes into top left slot 1 on the relay.

Terminal 2 top right is a single red going out to I don’t know where (maybe dome)

Terminal 3 lower right is single blue (maybe from dome? Or the open door circuit signal)

Terminal 4 lower left is 3 red wires and I assume those are coming in from the power source but one is coming in from the switch in the switch bank..

what's odd is a yellow wire from the switch in the switch bank is going into the headlight washer? Found that odd.


Any help much appreciated.

 

[milesc3]

One thing I found odd is there is a wire going from the relay to the relay

 

[milesc3]

these are the three ground wires all stacked together.

 

[milesc3]

That's how it's wired. I posted in the other thread but thought I would post here as well. The red wire going FROM the relay TO the relay impresses me as odd.

 

[NikP]

In a simple configuration each terminal has a simple single function. If I read the diagram on the relay correctly, terminal #1 is 12V power to supply power to the component connected on Terminal #2. Terminal #4 goes to ground and Terminal #3 should be the trigger to activate the power at #1 to route to the component at #2, thus turning it on.

It's confusing why there are multiple wires connected to #3. Also, the blue wire is confusing because it doesn't go to ground. Where does it go?

You mention another relay? And a switch bank? It sometimes requires multiple relays to achieve a certain function so that's not necessarily alarming. To really help you, you'll need to trace each wire end-end and let us know where's it's connected. Draw it out so we can see it. Pictured don't help us with the other end of the wire.

If wires connect to another relay include those connections as well.

 

[milesc3]

here's the relay

In a simple configuration each terminal has a simple single function. If I read the diagram on the relay correctly, terminal #1 is 12V power to supply power to the component connected on Terminal #2. Terminal #4 goes to ground and Terminal #3 should be the trigger to activate the power at #1 to route to the component at #2, thus turning it on.

It's confusing why there are multiple wires connected to #3. Also, the blue wire is confusing because it doesn't go to ground. Where does it go?

You mention another relay? And a switch bank? It sometimes requires multiple relays to achieve a certain function so that's not necessarily alarming. To really help you, you'll need to trace each wire end-end and let us know where's it's connected. Draw it out so we can see it. Pictured don't help us with the other end of the wire.

If wires connect to another relay include those connections as well.

The 3 white wires from terminal 1 carry the load to turn on the lights (two wires) and to power the override switch (one wire). The one blue wire is coming into terminal 4 presumably from the dome light/BCM to send a signal that the dome light is on thus turning on the rock lights (terminal 1). The power comes into terminal 3 from the battery (one red wire). A signal from the override switch (second red wire). The third red wire just runs from the relay to the relay which makes no sense to me. I believe since it's "hot" when the car is on that may be the culprit. It may be "charging" the solid state relay and leaving residual power to the output of terminal 1.

Said another way I don't know why anything is connected to terminal 2--the power to the relay is coming in at terminal 3.

The Switch bank is just the panel to the left of the steering wheel like the picture below (not exact). The override switch simply allows me to ignore the dome light (ie turn on the rock lights even if the dome light is off). That's all working fine.

The only issue is that when the car is running the rock lights are on regardless of anything else (done light, over ride switch, headlights...doesn't matter). If the ignition is on the rock lights are on.

 

[lx200inAR]

I would say everything looks fine. Terminal 4 is what needs investigating. Everything you have identified looks right.

Remember that terminals 1-2 are completely separate from 3-4. The reason you have a wire jumper between 2 to 3 is because that’s how your +12v for the load side is supplied. Terminal 4 must be connected to ground at some point. That is what triggers the SSR to connect the load terminals (1-2). Seems like when you have ignition on, that terminal is permanently attached to ground ( or possibly something with a voltage difference great enough to trigger the SSR between pins 3 and 4).

First things I would do is measure the voltage between terminals 3 and 4 with ignition on and off and try and figure out what term 4 is connected to.

 

[NikP]

I agree, we need to know where #4 is connected. There's something in that leg that is supplying ground when it shouldn't.

The jumper from #3 to #2 isn't the way I'd have wired it because it causes confusion about what the actual coil trigger is for the relay vs. what the power source is for the switch and the lights you're running. I prefer to keep those separate. Because of this confusion we're left trying to understand #4 because in a perfect scenario it's a simple ground but in this case it's more complicated.

I hope there are fuses in the circuit from the battery. As drawn, there's nothing protecting this. If a wire rubs bare on the frame, there's the potential for heat/fire destroying the switch and the relay and possibly more.

 

[NikP]

One thing I would do as a simple test, is remove the wires going to/from the override switch and see if this changes anything. This eliminates the possibility that the switch is bad or is wired incorrectly. If nothing changes then it's all about chasing down the #4 wiring and figuring it out.

 

[milesc3]

I would say everything looks fine. Terminal 4 is what needs investigating. Everything you have identified looks right.

Remember that terminals 1-2 are completely separate from 3-4. The reason you have a wire jumper between 2 to 3 is because that’s how your +12v for the load side is supplied. Terminal 4 must be connected to ground at some point. That is what triggers the SSR to connect the load terminals (1-2). Seems like when you have ignition on, that terminal is permanently attached to ground ( or possibly something with a voltage difference great enough to trigger the SSR between pins 3 and 4).

First things I would do is measure the voltage between terminals 3 and 4 with ignition on and off and try and figure out what term 4 is connected to.

term 4 is connected to the BCM under the dash by the brake pedal---presumably tapped into the dome light. See pic---that's where the blue wire runs.

 

[NikP]

I read your post in the other thread. It's a bit clearer.

Anyone tap into DOME light for rock lights in 2017 LC?

Hello all, just wondering if there have been any updates on the video tutorials here. This thread is definitely heading into a direction I was hoping it would. I understand, if not. Thanks! ditto bump

forum.ih8mud.com

Everything works as you want until you have the power on, correct?

With the power off, the running board lights come on with the dome. That verifies the trigger side of the relay is working fine.
With the power off, you can use the override switch and the running board lights come on. That verifies, the switch side works fine.

If when the power is on the running board lights come on, then it points to they simply tapped into the wrong "blue" wire under the dash.

You'll need a multi-meter to verify #4 behavior and to find the correct blue wire.

 

[milesc3]

I read your post in the other thread. It's a bit clearer.

Anyone tap into DOME light for rock lights in 2017 LC?

Hello all, just wondering if there have been any updates on the video tutorials here. This thread is definitely heading into a direction I was hoping it would. I understand, if not. Thanks! ditto bump

forum.ih8mud.com

Everything works as you want until you have the power on, correct?

With the power off, the running board lights come on with the dome. That verifies the trigger side of the relay is working fine.
With the power off, you can use the override switch and the running board lights come on. That verifies, the switch side works fine.

If when the power is on the running board lights come on, then it points to they simply tapped into the wrong "blue" wire under the dash.

You'll need a multi-meter to verify #4 behavior and to find the correct blue wire.

Thanks----this is very helpful. I was out of town all weekend but I appreciate this! I will check it out later. Are you saying the blue wire is delivering too much power?

 

[NikP]

Are you saying the blue wire is delivering too much power?

No, that's not what I'm saying. You have either one of two problems:

1. The blue wire is connected to a circuit that is on with the dome and also on with the power. You want to connect to a wire that is only on with the dome and is off at all other times. I read in other threads and it appears to be verified by the relay wiring that the #4 circuit is supplying ground. Some something is potentially supplying ground on this wire with the power on and also with the dome on.

or:

2: Your override switch is incorrectly wired and its providing power to the lights when the power is on.

You can verify if it's the switch by removing the green-to-yellow wire in your diagram from terminal #1. Then test to see if the lights are on when power is on. If the lights come on with power, then we'll focus on the switch.

Do this simple test and report back so we can take the next step to troubleshoot.

 

[milesc3]

Pretty sure it's #1 above. First the override switch works fin when ignition off. Also I unplugged the entire male part of the override switch and started the car and the lights still came on.