Tested with Thermo TOP Z/C and in good working condition.
Recommended for Windows XP as many car diagnostics devices.
Suitable for most Webasto heaters.

The black crocodile clamp goes to "-" of battery.
Red crocodile clamp goes to "+" of battery.

Small crocodile goes to testing pin No.2 of Webasto unit.

Needs free download of:

1. KKL cable basic driver
2. Webasto testing software

Must have tool as without regular servicing these heaters sooner or later became useless and is hard to determine where the problem is.