Anyone else have the 40 amp Corded Mobile Connector and have you had any issues with it?
Mine is about 10 months old and recently started to get very hot at the plug and ramp down the amperage. After a ~2 hr 40 min charge session the plug is measuring 122°F and the amperage has been cut down to 27 amps. I only noticed after it started completing my scheduled charge later and later and one day was not able to finish by the time I left.
I’ve tried emailing charging support but they just punted me back to making a regular service request.
Seeing as how it’s perpetually out of stock I don’t know if they can even exchange/replace it…
Based on your symptoms and experiences, this is potentially a tough one.
- The Corded Mobile Connector (CMC) is all one piece. Unless you are some kind of electrical engineering genius with a shop full of sophisticated tools, there is probably no way to take it apart without (a) permanently sacrificing it and (b) definitely voiding any warranty that might still exist. Tesla would never believe or accept that it wasn't your fault. So, first, don't be tempted do that.
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- Sounds like individual Tesla staff at charging support and at your regional service support are kicking the can down the road and refusing to take responsibility. Not a good sign.
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I live where there are at least three Service Centers within convenient reach. As a result I have found significant differences with the response and willingness to help solve a problem among the three on any given day. Therefore, if possible try more than one Service Center. Can SC staff test your CMC and confirm that there is a problem? DO NOT PERMANENTLY SURRENDER YOUR CMC. You simply want confirmation that your CMC does indeed have a problem and advice on how to proceed (in order to replace it with another CMC).
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- Unfortunately, the CMC as a piece of charging equipment is somewhat mysterious, and we have no definitive information about sales and popularity (with consumers and within Tesla Management) that I am aware of. Are we are talking about something of an orphaned product here?
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- So far offered for sale on the Tesla Shop Charging website from 2016 to today.
- Never upgraded or modified, that we know. Has curiously remained a Generation 1 product (able to charge at up to 40 amps).
- The need for this product has always sort of eluded me (and some others). After all, there was the original Universal Mobile Connector that also maxed out at 40 amps (e.g., when using its supplied NEMA 14-50 adapter-plug). Why then also offer the one-piece, more expensive CMC? What niche did it fill that the original UMC with NEMA 14-50 adapter-plug could not satisfy?
- Then, when Tesla began to realize that charging with a mobile connector at greater than 32 amps was not normally needed (i.e., with release of the 32a Gen 2 Mobile Connector in 2018), Tesla nonetheless continued to encourage mobile charging at up to 40 amps by still selling the CMC.
- And it was inexplicably expensive ($520) from 2016 to 2022. Why would Tesla go out of its way to (I presume unintentionally) hurt sales numbers with such a high price (higher than the much more sophisticated and charging-flexible Gen 2 High Power Wall Connector of that period) and stubbornly refuse to lower that price year after year? (Couldn't be just for profit. I doubt that CMC sales numbers were high enough for the money to be more than a drop in the bucket to Tesla.)
- Perhaps because of that high price, there is (only?) anecdotal evidence that the CMC is one of the least popular charging connectors and that not many people actually use it (e.g., see non-scientific poll here).
- To confuse matters, even though it routinely remained on the Tesla Shop webpage, it was often "Out of Stock,", as it routinely is right now after ironically finally being reduced down to the much more sensible price of $200 in 2022. Something is not right in all this.
- Pure speculation: Could it be that the CMC is an ignored or even generally unpopular product inside Tesla Management, but that it sprang into being as an EM-favored idea (like the stupid Model X FWDs*) and no one is able to kill it?
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- Regardless, you appear to have taken reasonable steps so far. And you have mostly answered the logical suggestions from other commenters. But humor me, here. Barring some sort of professional electronics testing with sophisticated diagnostic equipment of the internal components of your CMC, to be absolutely sure that the problem is within your particular CMC (and not in the wall outlet), I think you need to perform two more tests (which granted may be inconvenient for you):
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- Test your wall receptacle with another CMC. Does it also heat up or otherwise misbehave when using your wall outlet?
- Test your CMC at another 240v NEMA 14-50 wall outlet. Does your CMC heat up there?
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Is there anyone in your area who can lend you a CMC? And can you locate another NEMA 14-50 wall receptacle to use for a couple of hours? I recommend you make the effort to do these things, as I think the results of these tests will be important to finally convince Tesla (if anything will).
I fear that if you press the issue with Tesla too hard, too quickly--especially if you understandably get angry or aggressive--there might be only one outcome: to make you go away they will take away your claimed 'broken' CMC and replace it with a Gen 2 Mobile Connector. I assume that you do
not want that. By the way, I assume you paid $200 for your CMC, and not the original $520? If so, that will only encourage Tesla to simply replace it with a Gen 2 MC, which is now approximately the same price.
Anyway, the open question is:
How do you successfully persuade Tesla on this issue and get the outcome you desire--I assume a new CMC?
All I can suggest is that you tread lightly and carefully document all the pertinent evidence:
- List the aberrant symptoms seen. Measure these warm temperatures, if possible. Take photographs (e.g., of a digital thermometer registering excessive heat from the CMC)
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- Provide 'test' results for your wall outlet.
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- Your CMC heats up at your wall outlet.
- A Gen 2 MC does not heat up at your wall outlet.
- Important: A second CMC does/doesn't heat up at your wall outlet. (I assume it will not heat up.)
- Important: Your wall outlet has been carefully checked (by a professional, would be best) and there is no evidence of a problem. (Take photographs of wiring connections at the outlet.)
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- Plus results of further definitive tests of your CMC.
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- Your CMC exhibits the problems at all(?) charging rates (e.g., 40a, 32a, other?).
- Important: Your CMC does/doesn't heat up at a second wall outlet. (I assume it will heat up.)
- Is there any diagnostic equipment that the average electrician has that could indicate any internal problems with your CMC. (I assume not.) If Tesla Service can't/won't test your CMC, who else could?
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- Logical conclusion: all evidence points to there being some internal problem with your CMC.
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- Because its features are different from other mobile connectors, you respectfully request that your CMC be replaced with the same product.
- You understand that this may take awhile; you will wait. Meanwhile, definitely hold onto the evidence--your CMC--until the exchange can be made, if at all possible. (Otherwise Tesla may take your CMC and eventually replace it with a Gen 2 MC.)
Good luck with all this.
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* Full disclosure. I love my Model X. But--Oh boy!--do I wish it had a nice set of more reasonable rear "suicide doors." Automotive history is littered with the bones of gull-wing door engineering/marketing vanity projects that were invariably expensive and problem-prone.
Also, I own a CMC! (And I'd be using it today [with the rate in the car set at 32a] except that I had HOA problems, needed to move my charging spot farther away from my preferred parking location, and therefore needed the full 24-foot-long cable of a Tesla wall connector.)
