Help with Webasto

[Mrkentee]

   If perhaps someone here could assist me with this; My Webasto coolant heater locks out and won’t start many times without pulling the fuse and clearing the fault. Then it usually runs fine.
I bought this connector with the program to be able to see what the problem is and correct it.
I’m not an expert, and can’t find any instructions for how to hook this up. They say this is all I need to diagnose. Its a usb to OBD II. That connects to the three alligator clips. One is power, one is ground. The other goes to one of the posts, but not sure which. Or just how to go about it.
Thought maybe someone here might know. Thanks.