Only getting 4/12 A charging on Model 3 Gen 2 Mobile Connector

[Red Herring]

Tried plugging directly into 110v outlet in garage. Then confirmed I turned off all other appliances and devices on the same circuit. Then used a 25ft 10 AWG extension cord (yes a very thick 10 gauge) to try other 110v outlets in the house. Still only getting 4/12 A charging! Set max charging to 12A. House is 20 years old, but with a 200A service.

 

[Sophias_dad]

What sort of voltage is the car reporting? If its a daisy-chained outlet, any marginal connection along the way will rob voltage and be a potential fire hazard.

BTW, its a 120V outlet.

 

[Red Herring]

Its showing 119v. No other appliances are on the same circuit. Tried other outlets in the house as well. Still only 4/12 A.

 

[DeltaOne]

Its showing 119v. No other appliances are on the same circuit. Tried other outlets in the house as well. Still only 4/12 A.

Sounds like a 15 amp circuit. Have you tried a 120 volt / 20 amp circuit?

 

[Red Herring]

yes, tried on a 15 and 20 amp circuit, still 4/12 A.

 

[jjrandorin]

Tried plugging directly into 110v outlet in garage. Then confirmed I turned off all other appliances and devices on the same circuit.

Its showing 119v. No other appliances are on the same circuit. Tried other outlets in the house as well. Still only 4/12 A.

These two comments are not the same. "All other devices are off on that circuit" is not anywhere near the same thing as "this is a dedicated circuit". Please see @Sophias_dad 's post again, paying attention to the part I bolded. " I turned everything off on that circuit" is not the same thing as "its a dedicated circuit. Its likely its daisy chained as you, yourself stated " i turned off other appliances and devices".

What sort of voltage is the car reporting? If its a daisy-chained outlet, any marginal connection along the way will rob voltage and be a potential fire hazard.

BTW, its a 120V outlet.

 

[Sophias_dad]

4/12 and reading 119V is indeed a surprise. Is the 119 right when it starts (and isn't drawing power yet), or after it has stabilized at 4/12 ? If you watch it as it ramps up, does it ever get to 12 amps, and what is the lowest voltage that you see during ramp up?

 

[fortunex]

Is there any issue with heat? The mobile connector max is 120F, and will reduce amps if the temp in the garage is too high.

(this happened to me a few weeks ago)

 

[AlanSubie4Life]

Tried plugging directly into 110v outlet in garage. Then confirmed I turned off all other appliances and devices on the same circuit. Then used a 25ft 10 AWG extension cord (yes a very thick 10 gauge) to try other 110v outlets in the house. Still only getting 4/12 A charging! Set max charging to 12A. House is 20 years old, but with a 200A service.

Symptoms not exactly identical, but the last time we saw this it was a loose neutral in the mains (there were other warnings but it may depend on problem severity).
HELP! Getting 0-1kw from 200 amp service on 110v

Obviously, rule out the UMC by trying it at another house…

Rule out the car by charging elsewhere.

 

[mrau]

Might be a good idea to unplug the 120v adapter from the UMC, and then plug it back in until it is flush with body of the UMC.

This has worked for some folks, and is easy to do.

 

[brkaus]

Just to be sure - you have tried to move the amps up while it is charging? And it won’t go above 4?

 

[Red Herring]

4/12 and reading 119V is indeed a surprise. Is the 119 right when it starts (and isn't drawing power yet), or after it has stabilized at 4/12 ? If you watch it as it ramps up, does it ever get to 12 amps, and what is the lowest voltage that you see during ramp up?

It shows 119V when I first plug in and fluctuates around 117 at the lowest. It never gets to 12 amps, it starts ramping up and always stops at 4. I have tried moving up the max amps when charging with no luck.

 

[Red Herring]

Might be a good idea to unplug the 120v adapter from the UMC, and then plug it back in until it is flush with body of the UMC.

This has worked for some folks, and is easy to do.

I have tried unplugging the adapter from the UMC and let it sit for a while with no luck.

 

[Sophias_dad]

Your UMC or >maybe< in-car charger has failed. In-car charger failure is extremely unlikely in this case because they usually fail in 16 amp increments.

 

[mrau]

At this point I would try your UMC in a different Tesla. Also try another UMC at your home if you can. If you get a chance to try another UMC, be sure to swap pigtail adapters to see if it is the adapter or the UMC itself. If not possible, you may have to take it to a Service Center and let them try it out.

Don't forget to post how it turns out.

 

[Red Herring]

Thanks for everyone's feedback! I went to the Tesla service center and they determined my UMC was good, but my one week old Model 3 was defective. Now my Model 3 is in the shop and I have a Model X loaner.