can you please give us your dome light settings, are you parking lights on?

i wonder what is different with mine. the only thing diff i've done to this car since i bought it is unplugged the battery. i wonder if that resetted something.

 

It may be helpful to know what your vehicles are and what results you're getting.

ie.

IS 250 or IS 350
and
Premium Package or Sport Package

 

IS250 AWD Premium package only

I was getting the 12V reading regardless of the dome light button combos- I wanted to be able to test it with the doors closed but couldnt find a good ground- either that or it was reading 0V- which is correct based off of the manual

 

terp05,

BTW, my car is IS350 with premium package, NAV

Thanks for trying this out. To test it with the door closed, just simply press on the rubber covered switch that the door hits to turn of the lights. Hold it for a while, as it takes about 20 sec before the dome light is completely off.

You should get 12V as long as a door is open, but then again at another post, they say that on the Luxury package, the dome light has to be switched ON.

by BICHON
I honestly think they are not connected higher up in the chain on my car.

But, it does not matter anymore, I routed the foot light power to the connector. If you experience the same problem, let me know, I can tell you how I did it.

 

Can you post how you did with pics just in case some of us run into the same problem.
Thanks in advance

 

Good call on pressing in the button to test with the door closed- understanding the manual a little bit better, the +12V should always be present when the doors are open...The switching of the lights on and off is controlled by the ECU (which in turned gets its signals from the dome light buttons) and is connected to the negative end of the scuff plate circuit.

I happened to 'accidentally' take a screen shot of my computer and thought it would be useful for you and anyone- i really dont know where it came from (read: i'm playing dumb)

 

Hey lexus27 can you show us with pics what you wired to finally get your sills working?
Thanks

 

Edited: NOTE: IF YOU DO THIS MOD, THE SCUFF LIGHT WILL REMAIN ON WHEN YOU DRIVE.

Has anybody else installed their scuff plates and have it work plug and play?

terp05, thanks for the diagram. I did make a mistake on my previous post. I meant that the positive was present and not the ground signal as indicated by the diagram. Big duh for me. Since the diagram shows the ECU being involved in generating the ground (-), I suspect that it may not be set up that way from the factory since our cars were not originally equipped with the illuminated scuff plates. I do not want to wait any longer to resolve that issue.

So basically, I get the new plates, plugged them in, no lights. I tried different dome light switch setting combo and still no light.

I decided to provide the missing ground signal to my scuff plates courtesy of the foot lights. I believe that the scuff plate lights are also LEDs just like the foot lights and that’s why I was willing to try the connection.

Please try this mod at your own risk. I posted it here for info only.
It took me about 1 hour to do this. 40 minutes of that is probably due to me trying to figure out how to hide the wires nicely, I'm serious.

So here goes:

First disconnect the black (negative) terminal of the battery.
For all the connections/wire taps that you do, make sure they are actually connected.

I’ll start with the passenger side.
(1) Remove stock scuff plates. Remove the panel that holds the foot light. There are no screws holding it, just pull it down.

(2) The picture shows the backside of the panel. The only wiring you’ll see is one for the foot light. You will need to tap the red wire.


(3) Run your wire (mine is the black one) along with the factory wires (I also wrapped mine with black electrical tape to conceal and hold it) all the way to the scuff plate connector. Notice on this picture, you can’t even see my black wire. That’s because I hid it inside the fat wire loom that hides all the other wires.


(4) When you reach the scuff plate connector, you will need to cut the WHITE wire and connect the side that’s connected to the scuff plate connector with your new wire. Wrap the other end of the white wire with electrical tape just in case. Leave the other blue wire alone.

(5) Wrap the connection with more electrical tape. You might also notice that my scuff plate light connector now has a tie wrap on it. That’s just to keep it in place just in case somebody in the future yanks on it. Also, don’t forget to wrap the blue wire tap connector by the foot light. It looks so much nicer hidden.

(6) Connect new scuff plate wires to connector. Reinstall panel then the new scuff plate.

The Driver side.
(7) Remove stock scuff plates. Remove driver bottom panel. It is held by two screws.

(8) Locate the wires for the foot light (its coming from the grey connector, not the big rectangular white one), tap the red wire and run your wire all the way to the scuff plate connector. Take the time to hide your wire well. I did. I even used the fat factory wire looms to hide the wire like in (3).
[IMG] [/IMG]


(9) When you reach the scuff plate connector, you will need to cut the WHITE wire and connect the side that’s connected to the scuff plate connector with your new wire. Wrap the other end of the white wire with electrical tape just in case. Leave the other blue wire alone.
[IMG] [/IMG]


(10) Wrap the connection with more electrical tape (not shown in above picture). You might also notice that my scuff plate light connector now has a tie wrap on it. That’s just to keep it in place just in case somebody in the future yanks on it. Also, don’t forget to wrap the blue wire tap connector by the foot light. It looks so much nicer hidden.

(11) Connect new scuff plate wires to connector. Reinstall panel then the new scuff plate.

(12) You are done, enjoy. THEY DO TURN OFF WHEN THE FOOT LIGHTS TURN OFF.

 

if you connect it to the footwell light, then the logo comes on whenever the headlights are on...

 

DAMN you're right! I have only driven my car at night once in the last 3 weeks and did not notice the foot light is on when driving. This mod is easily removable. I can undo it in 5 minutes. For now, I will find the power lines for the door switch.

PLEASE DO NOT DO COPY THIS MOD, as jlin101 indicated that the scuff will remain on when you drive.

 

lexus27, seems to me you're pretty handy with the wiring. i think it would be easier for you to get the negative ground source from the door pinswitch. some pinswitches use negative ground signal. when the switch is open it grounded, when its closed its not. if someone can post the diagram for the door switch i know you can find the right wire to tap. my hats off to you for posting this for the rest us so we know its not completely a plug and play swap.

 

IS_250,

he he he. i already checked on the door switch, it is negative ground. you'll need a special screw (torx) to loosen the switch on our cars.

i'd wait to see another owner install theirs and find out if it is plug and play for them. the wiring diagram from terp05 shows the negative coming from the ECU, i wonder if it has to be programmed by the dealership.

 

honestly ive never looked at my door switch in the lexus. but im sure the wire could be found behind the kick panels or maybe one of the dome light wire could be ran through the a pillars? i installed a sub and amp in my IS when i first purchased it. not sure about you, but i get kinda nervous about doing any wiring in my new car. then again ive seen how some shops wire things up and prefer to do it myself.

 

Well, I could not resist trying it so I temporarily connected the ground line to the door switch and it worked too. This is a potential solution.

BUT, with the connection to the footlight, the scuff plates' operation is really classy. When you open the door, it takes the lights like half a second to go from off to full light, so its nice to see the transition. Turning off is the same, it dims then off, but again you won't see that since the door is closed. I wonder if this is how it operates with the Luxury package. Anyone?

With the door switch connection, the scuff plates illuminate immediately. I can't be that picky though, it's good enough.

FINAL CONCERN: I just want to be safe when connecting the scuff plate to the door switch. Atleast with the footlight connection, you know it is safe since it is meant for an LED. With the door switch, who knows what kind of current will be driving into those lights. Then again, maybe it doesn't matter. Who knows. I wish somebody can enlighten me on this. I just want these lights working.

If anyone gets the scuff plates to work plug and play, please let us know.

 

Giving some thought to this and looking at the wiring diagram i posted- the dome light shouldn't work if the scuff plates aren't connected- its an open circuit. Maybe there is a bypass for the cars without the plates? I also think we need a more detailed wiring diagram- I'm pretty sure the service manual has them but for some reason I can't pay for a day on techinfo....Anyone have the detailed wiring diagrams?

Also, looking at the diagram, the programming for the scuff plates in the ECU should be the same as the dome light- which lends me to believe the bypass issue might be the case