No, I didn't fire the plugs without ground. But what I did was to connect the battery backwards, by mistake. Yes, it was possible, due to an universal plug. Now, when I plugged it in wrongly the positive (red) lead was still in the center of the plug. Only the ground (black) was reversed and connected to the outside lead (orange), which is the signal, I believe. Luckily it didn't fry the module (I hope). But it looks like the sensor is toast. I guess I need to call CH and get me a new one.