# Door light dim, window raising early



## rDacted (Aug 12, 2020)

Hi,

So I've recently installed a mod to my model 3 which automatically presents the handles when I approach and 'suction' closes the doors if they're ajar. However one of my doors has begun behaving strangely. When I release the handle the car believes the door is closed and thus raises the window - even if the door is actually open. This prevents me from actually closing the door.

I've started to look into it and it would appear that the light at the bottom of the door is an additional symptom. The light is extremely dim. For those that don't know, the door light is critical to the proper functioning of the door. In testing with one of my working doors, I can replicate the symptoms if I detach the door light. However I've tested the LED on the door that's failing and it's fine. It seems like the voltage presented on the cable is much weaker than it should be.

I've reverted my changes to the door back to stock, and I still have the same issue. This leads me to think that the wiring harness has somehow been affected - but I'm unsure how, or where, this might have happened.

Does anyone have any experience with the wiring related to the door light, or know how this low-voltage situation may arise? A wiring diagram would be extremely handy if one is available.

Thanks!


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## Garlan Garner (May 24, 2016)

rDacted said:


> Hi,
> 
> So I've recently installed a mod to my model 3 which automatically presents the handles when I approach and 'suction' closes the doors if they're ajar. However one of my doors has begun behaving strangely. When I release the handle the car believes the door is closed and thus raises the window - even if the door is actually open. This prevents me from actually closing the door.
> 
> ...


Where did you get the unit from.

I have had a few of my customers experience the same thing.

1. swap the door light with the trunk light ( its the easiest to get to ).
2. did you perform the reset when you hold down the brake pedal and hold the scroll wheels down until you see the puddle light come back on.
3. Remove the main controller of your unit of the door handles from the CAN bus.

If those don't work.....please respond...I have some more ideas.

This is the kind of thing that makes a HUGE difference between the major 3rd party vendors.


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## JasonF (Oct 26, 2018)

No experience with this particular kit, but tossing in that a dim light that works fine when removed from the car means there is probably either a ground fault somewhere, or something is remaining engaged and drawing power when it shouldn’t be.


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## rDacted (Aug 12, 2020)

I've managed to get my hands on the wiring diagram. In it I discovered the light is inline with the 'ajar/open' sensor in the latch mechanism.

I managed to get a standard leaded LED (as used on a breadboard) and confirmed it works by using it on a working door, and confirmed it was dim when placed on the problematic door.

I then determined which side the fault was on by measuring the voltage between the positive side of the LED and the chassis ground (with the LED removed) It read a clean 12v. I then measured the resistance between the negative side of the LED and chassis ground with the latch open and closed - the readings were inconsistent but always high.

I repeated my test where I replaced the new latch with the original latch, and kept the LED inserted, and everything worked again. So I'm quite confident the new latch was at fault. Having just removed and reinstalled the original latch the door behaves fine again.

The vendor has been very responsive during the installation of their gear, so I'm confident I'll be able to get a replacement easily. It's just the language barrier was an issue when it came to diagnosing the problem.

For those wondering about 12v across the LED, my assumption is that the 12v supply is current limited. The final test I performed was bypassing the latch, running the LED between the LED+ voltage and chassis ground. The LED didn't blow, suggesting the source is current limited and the latch is a simple switch to control whether the circuit is open or not.

Thanks to all responders!


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