the speedo cable is connect to the gear box towards the back of the car.
and looks like this (lefthand side) http://www.mr2bitz.co.uk/engine_parts/tss/1.JPG
also
Error code 42
Vehicle speed sensor signal circuit (no speed signal for several seconds): while vehicle is operated under heavy load (tps/map/air flow inputs); speed sensor/circuit; ECU
The only trouble is that the error 42 is prob nothing to do with the speedo not working.
My speedo works when it wants to, more not working than working and i get no error codes.