hi i have a sierra 1.6 azura fitted with my own-built 2.0 pinto on 40's, its got a mental cam so id quite like 2 know what its revving at before i blow it up! being an azura it had a massive clock instead of a rev counter, iv been pissing about with a standard rev counter intrument panel from another sierra and the rev counter is 'live' when plugged in, as if u put the needle below the stopper it lifts itself up when the ignition is switched on; however it just sits at zero. iv tried running a wire straight from the coil, and that sparked and made the engine cut out. We then tried removing the rev counter from the gauge panel and wiring it straight off the battery and coil, but same results. for testing purposes i did the same with a cheesy halfords rev counter and it worked. anyone got any ideas? there are no spare pins on the dash plug, could the rev counter be knackered? cant imagine that causing the car to conk out tho