Will this Webasto Air Top wiring harness work with my Russian heater I purchased via Amazon (not from Butler Technik btw, you guys are just great) I'm having trouble getting correct info from Webasto US ... please help

Yes, this harness will work as an extension for your Webasto standard rotary controller. Our current understanding of heaters intended for the Russian market is that they are ONLY compatible with the Rotary controller - you will not be able to use this extension toconnect a digital Multicontrol or smatt controller unfortuantely. You would require to upgrade your main wiring harness and also possibly the heater internal ECU to allow connection of a Multi controller and diagnostics