New radiator fan

[Robin K-S]

Hi just replaced my radiator fan, had an old 2 pin one, but they don't do them anymore, so have replaced it with the 3 pin one. The guy in the shop said he thought the earth was the middle pin, but was unsure of the fast fan pin. Obviously 1 is slow & 1 is fast, anyone know which is which or do I just have to run it up to temp & try them out?
Any help appreciated.
Cheers
Robin

[Robin K-S]

Job done, fast is on the left, then slow, then earth. She now has a years MoT and is up for sale, if interested please see for sale section.
Cheers
Robin