Loud noise when charging

[ElectricEddy]

The problem is to replicate that at the dealership. Seeing is believing. Now that I know it happens reliably when the temp is below 10F I will set up an appointment accordingly.

Where is your location/ ambient temp? This is the first I've heard of this at higher temperatures. Have to wait for the rain and cold weather to happen ( may be a while off with the heat spell thats been going on for like 2 months now) before my SL will make that noise again.

 

[pkarza]

I had that happen once. I had just washed the car and I uplugged the 1772 - The breaker turned off the circuit - I reset it and then plugged it in and it was fine.

 

[Bob]

This is a wild guess, but if there is a 12V relay, 12V motor, or 12V pump, and it isn't getting enough voltage, then it could make that kind of noise. You mentioned that it happens when very cold. Check your 12V battery voltage when you have the problem. If it is <11V, that is almost definitely the problem.

When it's buzzing, see what happens when you jump a second battery onto the car. If it goes away, you've certainly pinpointed the problem.

Again, this is a guess, but if your battery is 2-3 years old, it's a possibility.

Bob