Connect a 10-30R plug to a L14-30R

I have some cable, a 10-30R plug and a L14-30 socket, which can connect to our L14-30 UMC adapter which I bought from TM to charge at Raceway Park. Can anyone tell me how to wire the L14-30 end of this adapter? It's non-trivial because it is going from a 3-pole, 3-wire plug on one end, to a 3-pole, 4-wire socket on the other. I've googled it but not had any success. I won't hold anyone liable for anything, just wondering if it is possible. PM me if you'd prefer to CYA ayway (understandable). Thanks in advance! - Ian

Ref: Universal Adapters - Available in North America Only (charging) Tesla Motors

 

Thanks for the quick help! After reading Scott's message last night plus one PM, I rewired my adapter cable [was all wrong, luckily no harm done] and got the car charging before I passed out. It saved the day. Today it was all ready for rides & Tesla Time!

I've also ordered the official adapter from TM, mainly because it seems you can't buy the loose 10-30 plugs any more (they're not "code", according to Home Depot & Loews) so I'll have to return the plug I borrowed from an air compressor.

Again thanks for the quick help, it really saved the day.

 

Apparently not, as I didn't connect neutral and the UMC is working fine. I wasn't explicitly ignoring Scott451's advice, but I got a PM separately telling me the minimum connections. I was about to change the wiring and thought I'd test it anyway; it happily charged all night without neutral connected.

It is a pretty ugly "solution", 10-30 wall socket adapted to 14-30 then through Tesla official adpater to connect that to the UMC. But the electrons don't seem to mind.