How to relocate 12V battery ground wire?

[No CO2]

I have a 2013 85kW car.

I am used my previous ICE car, and how easy it was to disconnect the negative wire from the battery to perform electrical service to the car.

Does anyone know where the negative wire from the battery grounds to the frame on a 2013 car? This is what I am interested in relocating. I would remove the existing wire, and run a new wire from the negative post of the battery to a "frame ground" location under the passenger side plastic cover in the frunk area.

Thanks,
Brian
San Diego, CA

 

[NewbyMaybe]

My 2014 has a jump connection near the nosecone. Check the threads on that ground on the 2013.

 

[No CO2]

Thanks Newby.

I am familiar with the nose cone jump set up.

I am trying to relocate the main negative wire on the 12V battery. One end will be on the battery, the other end at a new location. I am asking if anyone knows where the stock location is.

 

[ATPMSD]

Thanks Newby.

I am familiar with the nose cone jump set up.

I am trying to relocate the main negative wire on the 12V battery. One end will be on the battery, the other end at a new location. I am asking if anyone knows where the stock location is.

Just FYI, you are supposed to disconnect the HV battery loop before disconnecting the 12v ground wire. Unless you do that disconnecting the 12v ground will not necessarily shut down the 12v system.

 

[NewbyMaybe]

You could run the 12v ground cable up to a switch or disconnect behind the nosecone, then back to the battery. Maybe a large marine grade fuse to pull.

 

[airborne spoon]

for the 2013 is that where the battery is under the fender well by the passenger tire? Also how often are you doing service that requires you to disconnect the battery? Like I've done a lot of work on my car and I've only had to disconnect the battery for service when i was doing the heated wheel retrofit and front drive unit seals. Every other time I've worked on the car i left it hooked up because there was no reason to disconnect it. WTF are you doing so often its become an additional difficulty so much so that you want to put the ground point in a different location? Also you have the car in front of you why not just follow the negative wire to its termination point on the frame?

 

[NewbyMaybe]

Spoon, advice is valuable, scolding/trolling is worthless.

 

[No CO2]

Two months later, I finally got around to this project.
What do you gain if you do this modification? You don't have to remove the air box (and possibly drop its mounting screws into oblivion), and the "black wire ground disconnect" for any future 12 volt work on the car is much more accessible, thereby speeding your work.

How to relocate your 12 volt negative ground wire

Time required: 1 hour
Cost: $13 for parts - Amazon (one of the cheapest Tesla repairs you'll ever have)

https://www.amazon.com/East-Penn-00802-Battery-Cable/dp/B000BO9UHO

My car is a 2013, AP 0

1. Turn off car
2. Roll down driver’s window!!
3. Remove passenger side and windshield frunk trim plastic
4. Remove air filter cover
5. Lift trim around air cover
6. Remove qty 2 10mm bolts for air filter box. Do not drop screws.
7. Push down on top of airbox to release from two clips
8. Disconnect High Voltage fireman’s loop using small flathead screwdriver. Wait 2 minutes
9. Remove ground wire from negative terminal
10. Zip tie old negative cable out of reach
11. For any other smaller auxilary ground wires attached to the old main ground wire, I choose to cut these, and run them directly to the new ground point I'll be using, a front passenger frame strut (see photo)
12. Run and attach new Amazon ground wire.

For future 12 volt work, I only need to disconnect the bolt at the frame member.

Brian

 

[Gtech]

What about your electronic battery sensor?

 

[No CO2]

Gtech, I don't know much about an "electronic battery sensor". Never heard of it. Any wire that was connected to chassis ground is still connected to ground. It was the main 4 gauge wire and two auxiliary wires.
Brian

 

[Gtech]

Normally there is an EBS on your battery negative pole to measure capacity and life of your battery but I don't see that on your picture so I assume you removed it or not all Model S have them.

 

[No CO2]

Gtech, you are correct. My big mistake. Oops.
Putting these two EBS wires to ground, or not having an EBS, has bricked my car. I can't put it into Drive, with a "Service Required" on the front dash screen.
Just another DIY'er who doesn't know what he's doing.
I don't have time to fix it right now, but thanks for the input.
Brian

 

[No CO2]

Maybe someone can learn from my mistakes.

In trying to fix the damages...
- the 12V battery would not hold a charge, so I needed a new 12V battery
- Of course, I should have looked at the wiring diagram first, prior to starting this job. I was able to narrow it down to 3 fuses that may have blown. Using a voltmeter, I found the blown "F92" fuse.

The Tesla Mobile tech came out to my house. He replaced the 12V battery and blown fuse, and now back up and running. Total bill = $230. Very lucky that other major electronics or computers were not damaged.

I wired the car with the EBS properly, and kept the main 12V ground wire modification.

Brian

 

[No CO2]

I received a warning to replace the 12V battery, even though I knew it was brand new, roughly three weeks after the mobile tech replaced it.

This ground wire modification did not fully accomplish what I wanted (not to remove the air cleaner box) as I still needed to remove it to undo the fireman's loop.

I put the wiring back to stock, removed my modification, and the dash warning went away.

 

[Highxtech]

Maybe someone can learn from my mistakes.

In trying to fix the damages...
- the 12V battery would not hold a charge, so I needed a new 12V battery
- Of course, I should have looked at the wiring diagram first, prior to starting this job. I was able to narrow it down to 3 fuses that may have blown. Using a voltmeter, I found the blown "F92" fuse.

The Tesla Mobile tech came out to my house. He replaced the 12V battery and blown fuse, and now back up and running. Total bill = $230. Very lucky that other major electronics or computers were not damaged.

I wired the car with the EBS properly, and kept the main 12V ground wire modification.

Brian

Just wanted to say thank you for posting this. F92 being blown was causing a ton on errors for me (car was undrivable). Spent $250 on a battery after pulling what I thought was every fuse looking for an issue.

After seeing the fusebox diagram for the top of the battery I knew that was it.