06 Breva 1100 Starter Relay Issue

[Kiwi Dave]

The wire that feeds 12v to the supply side of the relay, where does it originate? KiwiDave is right, that circuit should have 12v on each side of the relay, 12v in, through the coil, 12v out, to be grounded by the ECM. (if I'm understanding this circuit correctly).  With the ECM disconnected.

Except that with the ECU disconnected, there will be 0 volts on both sides of the coil because the injection relay will not be energised.  That's why I suggested to remove the pink wire from the ECU, so it could be fired up.

[Kiwi Dave]

So concerned about this, I went and measured the voltage on my 1200 Sport which has the same arrangement.  The full positive battery voltage was measured on both sides of the relay coil before the start button was pressed.  So the 3.5v you are measuring is definitely an issue.

Using an ohms meter, measure the continuity of the pink wire from the starter relay to the ECU (unplugged).  It should measure very low.  Then measure from the pink wire to the frame of the motorcycle.  It should be infinity.  If either of these results differ, then please post the results here.

[dubtac]

So concerned about this, I went and measured the voltage on my 1200 Sport which has the same arrangement.  The full positive battery voltage was measured on both sides of the relay coil before the start button was pressed.  So the 3.5v you are measuring is definitely an issue.

Using an ohms meter, measure the continuity of the pink wire from the starter relay to the ECU (unplugged).  It should measure very low.  Then measure from the pink wire to the frame of the motorcycle.  It should be infinity.  If either of these results differ, then please post the results here.

Thanks Kiwi for testing that out on your bike for me and confirming something isn't correct with the wire. I will get back to everyone this weekend to test all of this out. I really can't put sentences together to explain how appreciative I am of everyone's help. Really everyone Thank You All So Much

[dubtac]

Using an ohms meter, measure the continuity of the pink wire from the starter relay to the ECU (unplugged).  It should measure very low.  Then measure from the pink wire to the frame of the motorcycle.  It should be infinity.  If either of these results differ, then please post the results here.

I followed your directions the pink brown wire to ECU connector ohm reading was real low which was fantastic, hooked the ECU connector back again, tested the pink brown wire to ground and it was infinity.
 I guess that leaves me with a cooked ECU?

[pat80flh]

Cooked Ecm? Not necessarily.  Ecm is always my last bet. Where does the wire on the other side of the coil originate? Before I condemn the ECM I would be checking that whole circuit three ways from Sunday, eliminating every other possibility.  What if the wire that feeds that coil has low voltage? Try piggybacking 12 volts jumped from  the battery + to the 12 v feed of that relay, see if that makes a difference.

  A disclaimer, I am new  to Moto Guzzis, so not familiar with them. But I have been turning wrenches professionally for 39 years.

[Kiwi Dave]

I followed your directions the pink brown wire to ECU connector ohm reading was real low which was fantastic, hooked the ECU connector back again, tested the pink brown wire to ground and it was infinity.
 I guess that leaves me with a cooked ECU?

I'm starting to think this way.  The final step is to disconnect the pink wire somewhere along its path, either at the ECU or the starter relay, but do not unplug the ECU.  Then check the voltage at the pink wire end of the starter relay coil and see if it's now jumped up to 12 volts.  If it has, then I'd be looking for a replacement ECU to at least try as a substitute.

[dubtac]

Cooked Ecm? Not necessarily.  Ecm is always my last bet. Where does the wire on the other side of the coil originate? Before I condemn the ECM I would be checking that whole circuit three ways from Sunday, eliminating every other possibility.  What if the wire that feeds that coil has low voltage? Try piggybacking 12 volts jumped from  the battery + to the 12 v feed of that relay, see if that makes a difference.

  A disclaimer, I am new  to Moto Guzzis, so not familiar with them. But I have been turning wrenches professionally for 39 years.

The pink brown wire starts at Pin 1 of the ECU to control side of the relay, the red black wire comes from pin 17 of the ECU, pin 17 powers the oxygen sensor, auxiliary injection relay control side, and starter relay. So I can safely say pin 17 is feeder for the starter relay.  I disassembled the harness completely following that pink brown wire to the end of the earth. Everything inside the harness was in excellent condition no kind of alarm.

[dubtac]

I'm starting to think this way.  The final step is to disconnect the pink wire somewhere along its path, either at the ECU or the starter relay, but do not unplug the ECU.  Then check the voltage at the pink wire end of the starter relay coil and see if it's now jumped up to 12 volts.  If it has, then I'd be looking for a replacement ECU to at least try as a substitute.

Well damn looks like an ECU is in my future any ideas were to source a used one?

[Kiwi Dave]

You could try PinWall Cycle Parts for one.

Or, what would be the harm in cutting the pink wire loose, and bring it out to a push button with the other side connected to chassis?  It would be crude, and maybe it mightn't have any interlocks for starting in gear or side stand down, but it might get you by for a while until an ECU becomes available.

I would free the pink wire from the starter relay, and wire in a new one to the new push button.  Then when you score a replacement ECU, it will be easy to return it to stock.

[pat80flh]

Conceivably you could just wire up a starter relay direct, to hell with that ECM.

Finding someone close with one to plug in would be nice.

A couple of things  I would check before I condemn the ECM, make sure it's getting good power and ground, a headlamp wired across at the ECM connector should burn brightly. I use a 9003 headlamp as test light. A voltmeter can show 12v and still not carry a load. Prove current can get to the ECM.

The last thing I'd do, get violent with it. Have someone hold that start button down and twist, tug, flex, and pull every connection you can lay your hands on. Bang the ECM with a screwdriver handle. Gently.