Main relay stays closed

[rogercar]

With everything off, my battery was going dead. Measured 1amp from bat with all off. Momentarilly disconnecting battery, current goes to 0. Unplugging main relay,current to 0. ECM feeds relay on either the yellow or green wire. Ignition on, yellow lead has current to relay. Ignition off, green lead has current to relay. disconnect battery, no current to relay. Connect battery, no current to relay.

Question: Is ECM bad or is it getting incorrect input causing this?

Tach reading 0. Removed tach and applied 5 volt signal to green lead, tach reads 10 (1000RPM) with 100 Hz input signal. Also the hour meter now advances with time. Looks like tach is OK. Checked green lead at console and reads 12 volts with engine off and stays on with switch off as with main relay problem above. With engine on at idle, there is still 12 volts on green lead but my frequency meter is picking up about 100 + hertz that must be superimposed on the 12v. Again, seems like signal from ECM is incorrect.

Are there any other tests? Can the ECM be tested out of the engine?

[rodbolt17]

out of the 15+ yamaha models that use a main relay can we ask which one you have?
my crystal ball broke and I lost my magic wand.

[rogercar]

Sorry about that. 2002F115LTRA

[rodbolt17]

I have seen that relay stick.
it typically leads to a funny shut off.
at key on the ECU wakes up and applies the ground path for the relay.
once on the ign coils,fuel pump and injectors are all fed via the red wire at the relay to the relays yellow/red wire.
at shut down the sequence kinda reverses with an addition to resetting the ISC valve before shutting down the relay by removing the ground path.

[rogercar]

recheck

I rechecked the wiring to the main relay against the wiring diagram that I have. The black wire is from one side of the relay coil and is permanently connected to battery minus(ground). Upon turn-on, power is supplied to the relay coil through the yellow wire. I traced the other relay input wire(green) and it goes to the smaller ECM connector. That same ECM connector has another green wire that goes to the tach. When the ignition switch is turned off, the ECM is still supplying power to the relay coil through the green lead. Also, at turn-off, the other ECM green lead is supplying 12volts DC to the tach.

With the engine running, the tach is not getting the proper signal.

It seems that the ECM is not doing its job at turn off but I dont know if from a faulty ECM or an incorrect input to some other input to the ECM.

I do have some other issues with engine operation although it starts easily with an unsteady idle but I want to resolve the electrical problem first.

[rogercar]

Update on main rlay and tach

I decided to replace the ECU and this corrected both the main relay staying closed and tach reading zero. I am next looking at the unsteady idle problem.