rev counter /tacho meter

[e30m3cabrio]

right guys my rev counter doesnt work.iv taken out the clocks and the is board iv put a volt meter on the batterys and both of the read 3.64 volts iv checked the board for cracks and flexed the board a little.iv also put a tester on the 3 point plug that goes in the back of the rev counter and ther is two lives and one earth i started the car up and reved the engine.checking for a pulse from any of the connectors ther was none!!!!!does anyone now were the signal comes from eather the ECU or the COIL.or even anything else i can check thanks perry

[Brianmoooore]

Comes from the ECU on a plain black wire, through pin 9 of the C101 engine loom plug/socket (beside the fusebox.) Tacho is very sensitive to a poor connection here.

[e30m3cabrio]

thanks il check tonight
Perry