7-pin Trailer Connection - No Power

[aeroguy]

Has anyone experienced no power coming from the 7-pin connector and/or know a fix? I have a service appointment in two weeks, but would be great to know if it’s an easy fix or something I’m missing.

None of the trailer lights turn on (running lights, turn signals, brake lights), brake assist doesn’t work, and there’s no voltage coming out of any of the pins on the connection. I also checked the 4-pin connector for voltage and those all read zero as well. I’ve tried every manual setting I can think of - manual lights on, turn signals, trailer mode on, powered sockets on.

I can manually put the truck in trailer mode (also the truck does detect a ‘heavy load’ and go into trailer mode automatically when we start driving with a ~5.5k lb trailer), but no power is getting to the trailer. We tested the trailer with another tow vehicle and everything still works fine on the trailer side. There’s no error codes displayed (checked both in regular and service mode).

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[aeroguy]

Figured out the problem, was a loose connector on the inside of the bumper. The blue connector in photo had to be snapped in. Fortunately this was accessible by reaching in through the right side opening in the bumper.

 

[YukonJack]

I been trying to see if Tesla has any current specifications for the 7 pin trailor connector. I can see it is controlled by this Trailer ECU but would like to know if the current is limited, fuzed, and protected.

Specifically want to know how much power the auxilary pin is capable of providing.

1. Left Turn/Stop Light (Yellow)
2. "-" Ground (White)
3. Trailer Brake Output (Blue)
4. Right Turn/Stop Light (Green)
5. +12V Auxiliary Power (Orange)
6. Running (or Side Marker) Lights (Brown)
7. Reverse Lights (Gray)

https://www.tesla.com/ownersmanual/...376-9257-2E9118AE1E1C.html#CONCEPT_BTD_M4G_JT

 

[aeroguy]

It’s definitely limited and protected (hence the need for touchscreen trailer mode resets from time). I assume just electronic fuses. 20A to 30A for the aux pin, depending on mode:

 

[YukonJack]

Thank You!

 

[Kryptek]

my

Figured out the problem, was a loose connector on the inside of the bumper. The blue connector in photo had to be snapped in. Fortunately this was accessible by reaching in through the right side opening in the bumper.

my trailer light stoppe working and this blue thing cannot be seen, i see something blue far to the left but its inserted

 

[aeroguy]

my

my trailer light stoppe working and this blue thing cannot be seen, i see something blue far to the left but its inserted

This is a better view of the connector into the 7-pin receptacle, I would try pushing it in (towards the rear of the truck) and if you hear a click then it’s now seated all the way. There’s also a blue connector into the trailer controller in that area, but that’s a lever locking connector that seems less likely to not be seated completely, plus it probably has an error code that would show up in service mode since the in/out wires are all in the same connector.

Trailer Controller Connector:

 

[Kryptek]

thanks will crawl under tonight have a peek

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