OBD Port and Readers

So I have a late 2001 Freelander and have tried two readers in the OBD port (I believe they are both ELM327 but I wasn't aware of there being any issues with that specific reader?).

I get nothing on both of them, after trawling through service bulletins I thought I struck gold with some not having the ground wired on pin 5 but after inspection of my own the splice exists.

Can't really think of much else I could try but I'm open to suggestions, otherwise I'm going to pen it down to the readers being incompatible

See here

That has crossed my path when searching for potential issues before and people have had decent results with the ELM327 readers on a petrol but I'm having hee-haw.