DIY fixing a failed charger in a 2013 P85 and how to fix and prevent failure

I figure I might write this up to help anyone else who experiences this.
First thing first, if you're regularly charging at 40A (or more), stop. If you don't need to charge this fast, back it off to 30A. The charger contains two 50A fuses and over time charging at 40A can cause them to fail even though the fuse ratings are not being exceeded. It's not uncommon for fuses to grow "tired" from cycling.

Now a bit about my setup. I have a 2013 Model S P85 with the dual-charger configuration and 100A service to my Tesla wall connector, so I can charge at 19KW (79A) at home. Since charging at full output causes the voltage to sag 10V, I typically charged at 40A where there's no sag (and little power lost to heat in my home wiring).

Last July I suddenly got an error when I went to charge and though the charger would click on, it wouldn't charge.
At this time I did not know how to get into the service menu, so I took my car to my local Tesla service and they said there was a "communications failure" with the primary charger. They had a replacement charger, but at $3500 I decided to see what other options were available. Supercharging still worked so this wasn't an emergency. While at the service center, I checked eBay and found a used charger for $400 which the seller said was working, which sounded a lot better than $3500 so I ordered it on the spot. There were cheaper ones but this one claimed it was working (which it was).
Tesla service won't install eBay parts but they did provide some tips on how to do it myself and pushed a software update they told me to install after replacing the charger. I won't go into details since the Tesla service manual covers this fairly well, other than to say that removing the back seat cushions was by far the hardest part. There was no clear explanation in the service manual and I couldn't find anything other than vague hand-waving online.
One suggestion I have is to buy some hose plugs and have some towels ready to mop up coolant. You will need them. Not a lot of coolant leaked, but I was thankful to have been prepared.

The online service manual is fairly clear on how to do this and I was able to swap out my old charger for the eBay one. Be sure to disconnect the 12V battery and pull the 12V loop before working on this, and carefully test with a good voltmeter to make sure all voltages are zero so you don't electrocute yourself. Speaking of the 12V battery, I replaced mine the last time it died with an Ohmmu LIPO one which, though expensive, is much lighter and easier to install and should last far longer than the usual AGM battery. I'm glad Tesla learned and made replacing the battery a lot easier on newer models. On my 2013, it's quite a pain to get to since it's buried under a bunch of stuff.

Once the new charger is installed, a software update is required. Tesla service pushed one for me, but if you know how to get into the service menu (hint, the password is "service") you can force a software update yourself. This will provision the car to work with the replaced charger.

The eBay charger worked like a charm, so I saved over $3000 by doing this myself.

Having a background in electronics and being an engineer, I decided to do a post-mortem on my dead charger. I thought it odd that Tesla said it was a communications error since it obviously was able to trigger my wall connector to turn on.
After removing the torx screws and poking around, I found one of the two 50A fuses was open. The only tricky part is to remove the plastic rivets for the insulating paper over the fuses and I accidentally broke one, though fortunately, a replacement was cheap.

I quickly went online and found the parts (links below). $79 later I have two new fuses, and while I have not tested my old charger because I don't want to go through the hassle of tearing apart my car again, I am fairly certain it's as good as new.
So if you regularly charge your car at 40A or more and you have problems charging but hear the wall connector click on, one of the 50A fuses would be a good place to start, and you could save yourself $3400 to replace both fuses first.

So if anyone is in the SF Bay Area and needs a generation 1 charger (or wants to add a second for dual charging), I'm willing to part with it, though I can't guarantee 100% that it will work (I'm 95% confident it will). As I said, the hardest part is getting the seat backs off and I never did find a good explanation on the trick to doing it, only a bunch of hand waving.
The plastic rivet holding the paper insulator are Esssentra Components SR-3045W.

It looks like the price of the fuse has gone up significantly, but the fuse is a Mersen A50P50-4 which I bought from
thefuseshop.com. If you find one fuse blown, it is probably best to replace both of them since the other fuse is likely tired.
Obviously if after putting everything back together again you blow another fuse, there's a bigger problem and eBay might be your best bet. Sadly I didn't take pictures during the process of replacing my charger, but here is a picture of the internal fuses.

Also, the part number for the on-board charger is 6009278-00-f and there are typically a fair number available on eBay, many for less than what I paid.

 

[aaronw]

I should add that anyone doing this should be aware that high voltages could be involved and to use caution. If you aren't familiar with using a volt meter and don't know how to protect yourself from high voltage, don't do this. During the process of doing this I never once saw any voltage on the battery side. Before I did anything, I used a good (Fluke 87) multimeter to check the voltages before I touched any of the high-voltage contacts. Don't use a cheap multimeter, it might not handle high voltage (even if it claims to). I also made sure to pull the high-voltage loop in the frunk and disconnected the battery. This will cause the contactors in the HV battery to open, though as I said, always verify with a voltmeter before proceeding and make sure everything in the car is dead. I also used the power-down option on the touchscreen before disconnecting the battery. If you don't understand or respect high-voltage, don't do this since this could kill you.

 

[MlTaylor619]

Was just quoted $4285 to replace HV charger/distribution unit on a one owner 2014 Model S, 102k miles. It charges on lower 220v and 110v, but not at the superchargers. Wow, what an expensive repair! That, the MCU replacement, and door handles...making me rethink my commitment to EVs.

 

[CMPT PAD]

I am quite handy but I don't touch 240V
I paid $900 to a certified retired electrician to install the Tesla wall charger in our garage. Using it since Dec 2022, no problem
Tesla owner user manual said I can charge anytime I want at 48A. So that's what I been doing. Someday they come out with a Solid-state battery instead of 2170 or 4680 then that would be the day,

 

[maximizese]

Was just quoted $4285 to replace HV charger/distribution unit on a one owner 2014 Model S, 102k miles. It charges on lower 220v and 110v, but not at the superchargers. Wow, what an expensive repair! That, the MCU replacement, and door handles...making me rethink my commitment to EVs.

Costs less than 1/10th of that for a used charger/distribution unit on eBay. Not sure if special software is needed to pair the unit with car or if it's a simple plug-and-play component. I wouldn't consider the MCU and door handles issue a knock against EVs...it's just a knock against Tesla. While some of the repairs are uncomfortably expensive, I'm seeing a very slow trend that these repairs are dropping in cost as the cars become more ubiquitous. I remember the days when door handle repairs were close to $1K each. Now there's 3rd party support and I believe Tesla's gen 3 door handle replacement is below $400. I am sympathetic though, I don't think anyone wants to see a quote for $4K+ for repairs. Personally I would send an email to WK057 to see if they have a solution for you.

 

[tps5352]

I figure I might write this up to help anyone else who experiences this.
First thing first, if you're regularly charging at 40A (or more), stop. If you don't need to charge this fast, back it off to 30A. The charger contains two 50A fuses and over time charging at 40A can cause them to fail even though the fuse ratings are not being exceeded. It's not uncommon for fuses to grow "tired" from cycling...

Thank you for this informative post. In the months before (March 2021) I bought a Tesla, I was (of course) a "newbie" and somewhat obsessed with the idea of eventually charging at the highest possible level (which turned out to be 48a).

After finally getting the car, I began to realize that the maximum charge rate is not normally necessary or desirable.

• The average US driver goes maybe 45 miles a day.
• We are told that for best long-term battery health we should normally charge to, say, a maximum 80% of capacity.
• On most days, cars probably return home with some significant remaining level of charge (e.g., 25-75%), so complete 20% to 80% charging is not always needed.
• The average person sleeps overnight, and their car is often parked unused for, say, around 12 hours.
• Charging (from 20-80%) at AC 240v takes several hours, regardless of the amperage. Charging at 40 or 48 amps is quicker, yes; but still not even close to being Supercharger (DC high voltage) fast.
• So as long as the car can be fully charged within that 10- to 12-hour period of inactivity (and it will usually be less because of the facts listed above), it doesn't matter whether you charge at 48a, 40a, 32a, or even lower.

And there are advantages to using lower amperage.

• Less (heating/cooling) strain (over time) on all parts of the charging system (circuit breaker, house wiring, components of the wall receptacle or connector, charging cable and plug, and various vehicle components.
• This is especially important at the wall outlet (where house wires are connected by tightening screws to metal fittings) and, as you have now instructed us, the car's fuses.

Where we truly need power (= speed) is for on-the-road charging. The sooner charging routinely takes no longer than gasoline refueling, the better. So when traveling we use DC fast chargers (and they continue to improve). But for most households, the fastest AC charging rate is just not necessary. You can see an apparent realization of this by Tesla itself, in the way home charging equipment power has come down over the years.

• Maximum wall connector power dropped from 80a to 48a (2020)
• Maximum mobile connector power dropped from 40a to 32a (2018)
• You do not hear "future-proofing" (over-building to prepare for future cars) discussed as it once was.

Human beings are governed by both needs and wants. In the United States (and other places), "bigger is better" has been a common theme, and manufacturers have long recognized the psychological/marketing advantages of giving customers what they want. But in this case, when an actual need is questionable, long-term safety and power-wastefulness concerns take precedence.

I am quite handy but I don't touch 240V
I paid $900 to a certified retired electrician to install the Tesla wall charger in our garage. Using it since Dec 2022, no problem
Tesla owner user manual said I can charge anytime I want at 48A. So that's what I been doing. Someday they come out with a Solid-state battery instead of 2170 or 4680 then that would be the day,

I hear you. Tesla provides cars can charge at up to 48 amps and Generation 3 wall connectors provide that power. So what's the issue? See above. Why charge at that rate if it is not needed? I fully acknowledge that some households need the fastest charging possible. Most do not.

It is up to individual drivers to assess their situation, and budget, and set up their home charging system accordingly.

In my case, I have a Model X and Tesla Generation 2 High Power Wall Connector (I needed a 24' cable) attached to a 50-amp circuit (#6 house wiring), but the car is instructed to charge at 32 amps. (I need to check and see if I can do 28a or 24a.)

 

[CMPT PAD]

If by laws we are allowed to drive 70mph on freeway then why drive at 45mph UNLESS it's foggy and could not see anything in front of us.

 

[Kapil Khanna]

Hi Aaronw - I have the same exact issue and Tesla had the same suggestion to replace the master charger for around US$ 3k. I am not at all handy . I am trying to find someone in the Dallas area to help with this.

 

[Troy Hobbs]

I figure I might write this up to help anyone else who experiences this.
First thing first, if you're regularly charging at 40A (or more), stop. If you don't need to charge this fast, back it off to 30A. The charger contains two 50A fuses and over time charging at 40A can cause them to fail even though the fuse ratings are not being exceeded. It's not uncommon for fuses to grow "tired" from cycling.

Now a bit about my setup. I have a 2013 Model S P85 with the dual-charger configuration and 100A service to my Tesla wall connector, so I can charge at 19KW (79A) at home. Since charging at full output causes the voltage to sag 10V, I typically charged at 40A where there's no sag (and little power lost to heat in my home wiring).

Last July I suddenly got an error when I went to charge and though the charger would click on, it wouldn't charge.
At this time I did not know how to get into the service menu, so I took my car to my local Tesla service and they said there was a "communications failure" with the primary charger. They had a replacement charger, but at $3500 I decided to see what other options were available. Supercharging still worked so this wasn't an emergency. While at the service center, I checked eBay and found a used charger for $400 which the seller said was working, which sounded a lot better than $3500 so I ordered it on the spot. There were cheaper ones but this one claimed it was working (which it was).
Tesla service won't install eBay parts but they did provide some tips on how to do it myself and pushed a software update they told me to install after replacing the charger. I won't go into details since the Tesla service manual covers this fairly well, other than to say that removing the back seat cushions was by far the hardest part. There was no clear explanation in the service manual and I couldn't find anything other than vague hand-waving online.
One suggestion I have is to buy some hose plugs and have some towels ready to mop up coolant. You will need them. Not a lot of coolant leaked, but I was thankful to have been prepared.

The online service manual is fairly clear on how to do this and I was able to swap out my old charger for the eBay one. Be sure to disconnect the 12V battery and pull the 12V loop before working on this, and carefully test with a good voltmeter to make sure all voltages are zero so you don't electrocute yourself. Speaking of the 12V battery, I replaced mine the last time it died with an Ohmmu LIPO one which, though expensive, is much lighter and easier to install and should last far longer than the usual AGM battery. I'm glad Tesla learned and made replacing the battery a lot easier on newer models. On my 2013, it's quite a pain to get to since it's buried under a bunch of stuff.

Once the new charger is installed, a software update is required. Tesla service pushed one for me, but if you know how to get into the service menu (hint, the password is "service") you can force a software update yourself. This will provision the car to work with the replaced charger.

The eBay charger worked like a charm, so I saved over $3000 by doing this myself.

Having a background in electronics and being an engineer, I decided to do a post-mortem on my dead charger. I thought it odd that Tesla said it was a communications error since it obviously was able to trigger my wall connector to turn on.
After removing the torx screws and poking around, I found one of the two 50A fuses was open. The only tricky part is to remove the plastic rivets for the insulating paper over the fuses and I accidentally broke one, though fortunately, a replacement was cheap.

I quickly went online and found the parts (links below). $79 later I have two new fuses, and while I have not tested my old charger because I don't want to go through the hassle of tearing apart my car again, I am fairly certain it's as good as new.
So if you regularly charge your car at 40A or more and you have problems charging but hear the wall connector click on, one of the 50A fuses would be a good place to start, and you could save yourself $3400 to replace both fuses first.

So if anyone is in the SF Bay Area and needs a generation 1 charger (or wants to add a second for dual charging), I'm willing to part with it, though I can't guarantee 100% that it will work (I'm 95% confident it will). As I said, the hardest part is getting the seat backs off and I never did find a good explanation on the trick to doing it, only a bunch of hand waving.
The plastic rivet holding the paper insulator are Esssentra Components SR-3045W.

It looks like the price of the fuse has gone up significantly, but the fuse is a Mersen A50P50-4 which I bought from
thefuseshop.com. If you find one fuse blown, it is probably best to replace both of them since the other fuse is likely tired.
Obviously if after putting everything back together again you blow another fuse, there's a bigger problem and eBay might be your best bet. Sadly I didn't take pictures during the process of replacing my charger, but here is a picture of the internal fuses.
View attachment 935035
Also, the part number for the on-board charger is 6009278-00-f and there are typically a fair number available on eBay, many for less than what I paid.

Great advice! Thank you for taking the time to share!

 

[maximizese]

Hi Aaronw - I have the same exact issue and Tesla had the same suggestion to replace the master charger for around US$ 3k. I am not at all handy . I am trying to find someone in the Dallas area to help with this.

I know Texas is a big place, but I would contact Recell to see if they provide a service or recommend someone in your area for the job. Perhaps they can inspect both your new and old component too to see if there's a problem upstream or just a sole worn component.

 

[bvictor29]

Thanks for this informative post. Just was diagnosed with the same issue. Quoting $2,200 for part plus about $365 labor + tax... really tough decision. Honestly I would just accept lower charging speeds (supercharging "phase" still works fine), bigger issue for me is that for some reason they cant push any firmware updates because of this problem, despite trying many attempts to bypass this error. Did anyone else have that issue or better yet have a technician figure out a way to bypass it?

 

[Temour100]

I know Texas is a big place, but I would contact Recell to see if they provide a service or recommend someone in your area for the job. Perhaps they can inspect both your new and old component too to see if there's a problem upstream or just a sole worn component.

I’m in Houston and successfully completed mine.

 

[Temour100]

Hi Aaronw - I have the same exact issue and Tesla had the same suggestion to replace the master charger for around US$ 3k. I am not at all handy . I am trying to find someone in the Dallas area to help with this.

I’m in Houston and I recently did mine!!

 

[Temour100]

Thanks for this informative post. Just was diagnosed with the same issue. Quoting $2,200 for part plus about $365 labor + tax... really tough decision. Honestly I would just accept lower charging speeds (supercharging "phase" still works fine), bigger issue for me is that for some reason they cant push any firmware updates because of this problem, despite trying many attempts to bypass this error. Did anyone else have that issue or better yet have a technician figure out a way to bypass it?

I pushed the update myself manually but I forgot how I did it exactly. I will look into it, I read a forum on TMC and followed the instructions through there. I’ll update if I find anything but the process was something like this:

1. Drive to Tesla service center location
2. Put car into service mode (look it up if you don’t know how, hard to explain over text)
3. Change one setting (which I forgot) and it will push a manual update to download onto car.
4. Let the update download but don’t install just yet!!!!
5. Drive home and complete the replacement SAFELY and boot the car up and install the update.
6. (Optional) Ensure everything works and if you really want go to Tesla and make sure there is nothing wrong with the car.

 

[Jose Garcia 54]

Using this post and the MX service manual, I swapped the an eBay onboard charger with my original charger on my 2017 Tesla X.

The update did not succeed. And my 12V battery died since the HV system was disabled during the failed update, preventing the 12V battery from charging.

I had Tesla mobile service come and they explained that the charger I put in might not be compatible due to a VIN blacklist on the ebay charger or Tesla changes their firmware to prevent onboard chargers from being swapped. They say an error "onboard charger MIA" was showing when they tried to update my car via CAN.

Looks like i will have to tow my X to service and pay for a new charger. Hopefully they discount the labor since the car is already opened up.