Greetings to one and all, new to the Club and the MX5. We have had an 06 (NC) 2.0 Sport for three weeks and are very happy with it.
I have found it very difficult to source wiring diagrams for any UK spec models. I am specifically trying to trace the VSS ( vehicle speed sensor) wiring to the instrument binnacle. ( think it’s only one feed/pulse wire) The speedo is occasionally erratic or stops for a rest then works ok, I am guessing at a wire break or similar.
Otherwise if the US one does not mimic the UK cars wiring, log on to the Mazda European Independent Operators Portal and pay a few Euro for an hours time to download the UK wiring diagram.
I agree with your thought on the possible sensor fault, need to chase the wiring through to be sure though, its a little difficult to know where to start with the multi meter without the wiring diagram and some colours.