2014 TL tech package
So I was trying to run a power cable from the battery to the trunk to connect an aftermarket amp last week. I disconnected the battery, ran the cable through the firewall, into the cabin, under the dash, down the wiring path(left drivers side at under the plastic paneling), and into the trunk. It started raining, so I rolled up the drivers side window(it had been open during the light rain for about 8 mins), closed the door and called it a day. The next morning, I went to continue the job, but noticed that my keyfob would not unlock the car. Strange. Manually opened the door, got into the car and tried to start it. No joy. The power button illuminated and the dash showed the 'Press brake +' button message, but the car would not start. Used my wife's car and jumped it. It then started up. Got inside and noticed that the navigation/stereo was not powering up. Again, strange. Checked other items. Everything worked except the center panel was not illuminating (A/C & Controls work, just no lights). Figured a fuse had blown. Checked fuses in all 3 locations, none were blown. Put a new battery in, and the car started like normal, but the internal issues were unchanged. Work got busy so I had to pause my investigation. Drove it to and from work fine with no problems. *I did notice that my MPG indicator started at zero each time I started the car. (Never paid much attention to this before so this might be normal) At the end of the week, I got in the car to head to work, but it would not start. Same behavior as before. Jumped it, and it cranked up. By the end of the day after sitting in the parking lot, the battery was dead again. Something is draining the battery. A short somewhere maybe? I tried to connect my code reader to see if it was throwing codes but the reader did not power on when I turned on the ignition. There is no power going to the ODBC connection. I finally took it to the dealer and they visually checked some things out, and hypothesized that the passenger side fuse box was the cause. They replaced it and added a new battery. No improvement. Now they are saying that the wiring harness between the engine compartment and cabin might be damaged. They would have to take the engine and dash out to get to it, etc The part is a few hundred but the labor will be pretty extensive. They are giving me a "ballpark" of $2900 to fix it. They aren't even certain for sure if that's the actual cause.
So in a nutshell, the car drives fine, everything works like normal except:
Keyless
Navigation
Stereo
Center console panel not illuminating (but the a/c and controls still work)
Battery drain when the car is turned off
Does anyone have any ideas what could be causing this?

 

Disconnect your new amp cable on the off chance that it snagged something sharp to short to ground.
Charge your battery and connect either a volt meter or amp meter and look for a change in voltage or current draw as you remove fuses.
Off topic but I once had the metal ring from a plug in 12 volt accessory plug fall off and into my cigarette lighter socket causing a dead battery if my truck sat for a week.....wasn’t enough to blow the fuse, was enough to drain the battery over several days... took a little while to find...

 

yes, check all under hood fuses and in cabin fuses.
then check on the MICU.

 

Thanks for the early responses guys! I checked the fuses and they are all good. Which MICU deals with the components that are not working in my scenario? Since they replaced the passenger side, that only leaves the engine and drivers side.

 

i'm only guessing, I didnt really read the story.
sounds to me like you're looking for a short somewhere, which someone, maybe you would have to go in and investigate and find...thus the $2900 labor charge

 

Disconnect and remove everything, that is aftermarket, from the car, and restore the car wiring back to stock form. Then check again if the mysterious current draw is still occurring or not.

 

Thats the weird part. Nothing was ever connected. Just ran the power. through the car I removed the power cable and still the same. I guess I might just have to bite the bullet and let the dealer try to locate the short.

 

I think the MICU (driver's side fusebox) is more suspect than the passengers fuse box, i have no idea why they decided to replace that one first instead of hte driver's side on


i'd try and replace that before anything else

 

Is there any chance that you could have driven a screw into part of your cars existing wiring while running your amp cable?
I would double check around everywhere that you worked while running the amp cable to see if something got disturbed. Any chance a wire was rubbed while pulling in the new amp cable?

 

hey did you find out the problem?