Mahindra XUV300 cabin light issue: Car battery drains fully overnight

I was told by the service centre that they have connected the LED scuff plates (official Mahindra accessory) to the cabin light.

BHPian Goandiaries recently shared this with other enthusiasts.

I have a December 2020 manufactured XUV300 with the current odo close to 48k kms. At the time of purchase, I installed the official Mahindra LED scuff plates accessory through the dealer. The power for this accessory was sourced from the cabin lamp wiring with a separate fuse (which I learned after the issue, to be honest) – which switches off once I start or lock the vehicle. Normally, when the cabin lamps are in auto or door mode, the lamps in the cabin turn on and off while opening and closing the doors, respectively. The manual switches, on the other hand, keep the lights on while you are inside the car and turn off automatically when you lock the car.

Now to the symptoms

I remember the cabin lamps in my car working normally at least till the end of March 2023. Fwd to mid-April, after a 400km trip, park the car (power off the dashcam) and unlock the next morning only to find the battery dead within 24 hrs of the trip, with a battery voltage of 9.9V.

RSA arrives within an hour to jump-start the car with their battery pack, and I charge it for an hour by driving around highways. Meanwhile knowing that I had no other extra fittings in my car other than the dashcam and the LED scuffs, that could possibly drain the battery, I removed the power supply to the LED plates. However, the battery kept draining and eventually proved useless as it did not hold cranking voltage even for 2 days without driving. The battery was draining even when it was not connected to the car! This proved to be the first major issue in the car which impacted the battery for worse and I had to replace it.

The issue

I realised that the LED scuffs did not turn off while holding the door switch and locking the car. I was told by the service that they have connected the LED scuffs to the cabin lamps and the LED goes off around 10 mins when the doors are open (which I have noticed sometimes while washing the car) and similarly goes off while locking the car as well.

To avoid taking chances on the new battery, I removed the separate 5A fuse in the LED scuff wiring. And thought that I will check the wiring during the 50k service. One fine day my son leaves the rear cabin lamp on in a basement parking of a mall, and I notice that the lights do not turn off while locking the car. Upon returning home, checked the cabin lamps and realized that the lamps in manual mode did stay on for over 20 minutes that I checked. I strongly suspect that this issue cropped up at some point of time late March or early April, and this slowly killed the battery. I did not notice because the cabin lamps are usually in door / auto mode which works PERFECTLY fine till now and LED scuffs are not visible with closed doors.

The video at the start compares a normal and the affected vehicles’ lamp functioning.

Though I have informed the Mahindra service personnel who looks at electricals (looks like I provided them with a new issue), I thought it would be a good idea to figure out the possibilities for such a malfunction. Experts here can provide their input, please!

Additional info

Here's the fuse box information of my car. I don't see a separate fuse for the room lamps.

I did check the Ssangyong Tivoli’s wiring manual (considering that most of the wiring for existing features are similar - I also assumed this looking at the layout of the fusebox in both) – but I couldn’t understand where it could go wrong with the help of the circuit diagram. Am attaching a pdf of the interior lamps circuit here.

Here's what BHPian Omkar had to say about the matter:

Cabin light staying on is not uncommon, but your case does seem a bit strange because of the added scuff plate. I'm guessing that you had the scuff plates installed back when the car was new and the issue that you are facing is more recent.

The common reason for the cabin light staying on would be the door latch/actuator might've gone bad. Maybe the door isn't getting closed properly. Did you notice a door-ajar warning on the MID? That could lead to the cabin light staying On.

But if that's fine and the fuses and relays are fine too, and you still have a battery leak then there might be some other electrical issue which would need a proper electrician to inspect.

Please do update what the electrician at Mahindra says about the whole thing.

Here's what BHPian Goandiaries replied:

Thanks for the reply, Omkar! Yes, the scuff plates were installed at the time of delivery of the car in 2021 Jan. There were no issues till recently. However, I did notice that sometimes the scuff plates used to stay off/glow very faint (randomly, on all 4 sides) even while opening the door. I dismissed it as failing LEDs. Once while I removed the floor trim to fix the dashcam wiring, I noticed that the LEDs intensity was back to normal! Again, this happened somewhere in the month of March 2023 and I did not give it much thought!

There's no issue with the door actuator anytime. Whenever the MID says the door is open, it is indeed open.

Regarding the fuse, I did not open and check the memory fuse yet, since all other functions routed through the PF2 fuse (please refer to the fuse box image in the original post) are working fine. Do you think it is a good idea to remove it and check for once?

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