Looking at the solenoid connector, there are 2 wires, a violet/white and a grey/black. The violet purple should have 12V and is on the same fuse as the stop lights and horn. Check there is 12V there, preferably with a test light - a 21W bulb is good for this, it should light up brightly. A meter can show volts when no load but won't indicate a high resistance in the circuit. The grey/black wire gets a connection to earth from the ECU when the starter button is pressed AND the bike is in neutral OR the bike is in gear AND the stand is up AND the clutch lever is pulled in. Note the starter button doesn't operate the solenoid directly, it signals the ECU. Again, a test light is good to check the operation of this circuit. Connect one side of the bulb to battery +ve and the other to the grey/black wire. The bulb should light when the starter button is pressed provided the above conditions are met. It is probably a good idea to remove the 3rd party alarm to be sure that that isn't the cause of the problem.
Apologies, getting confused. I have a power commander with an extra terminal. There is an extra small wire but it's crimped into the battery terminal.
There is a small earth wire that attaches to the forward ecu bolt. According to Chrisw, this has to be clean and tight or it will cause all sorts of issues.
1/ Find alarm and all associated wiring 2/ Trace all wires from alarm back into the loom and disconnect / remove slowly and carefully 3/ Reconnect wires, solder and waterproof correctly 4/ Re-wrap wiring loom with loom tape 5/ Take alarm and all the crap you've just removed and bin it. Be careful to set fire to it all! (Hate the things I do, no one even looks out their curtains when they go off and they cause so much feckin grief) 6/ Try ignition again with freshly charged battery. 7/ After you switch off the engine, drink celebratory beer and pray for dry clean roads. Mart
Now you say that I did see a loose earth wire that wasnt bolted to anything when I first got the bike and I assumed it was to be connected to the engine so i removed a bolt on engine and bolted it there. It was located near the ECU now that I think about it. I bet that's the earth wire you are talking about and it is suppose to be bolted to the ECU.
Thanks for that info Martin I'll run through this and 100% this is somthing I had planned get rid of the poxy alarm lol
Even if loose, it’s a nightmare. There’s a hole on the ECU that it’ll fit right onto. Almost certainly that’s the culprit then. Thankfully the 749 is a doddle to get the panels off. Good luck. Mart
It makes sense and i bloody hope so I started to get some grey hairs there! Almost catching up with you Martin Thanks everyone
Actually, thinking about that for a few mins. From distant memory (when I worked on my own 749S and R) if the ECU does not have the earth connected at all, you’d get no dashboard or anything happening at all. Can anyone verify that? (It’s been a while!) Can you post a picture for us all to see? We might be able to figure it out from there. Mart
I'm not sure about the dash but if the ECU earth is disconnected there is definitely no fuel pump relay and probably no starter.
The earth is connected but not to the right place. I personally don’t know why it needs to be earthed to that bolt but I’m certain that Chrisw insists that it has to be and that the connection must be clean and tight. Luckily it’s relatively simple and costs nothing to put it right and see if it does the trick. Fingers crossed
I earthed the ECU last night and it has now started to kick over as it should when pressing the start button. EXCELLENT!! But now I'm getting engine management light on and fault code is 16.0 Pump Relay. if this is referring to the Relay behind the battery box I did change this but when fitting that earth it did get tugged and pulled out the way a few times so Im thinking maybe i have pulled a wire out or somthing so that is my job today lol 1 problem solved onto the next
Glad the ECU earth thing helped. I replaced that relay recently but with the wrong type! They both look the same and have the same pins and same size and shape. However, one has a resistance in the circuit and one has a diode. According to Derek, Ducati for some reason use different polarity to everyone one else, so the diode type won't work, as s diode will only allow current to pass in one direction and in a Ducati it's the wrong direction. Check the packaging for what type you have. Also, there should be a diagram on the relay itself to show whether there's a diode or resistor in there.
Only in some instances, this may be one of them. The diode doesn't prevent current flowing in this case but effectively shorts out the relay coil but Error 16.0 means "Fuel pump relay disconnected". So most likely the connection to the relay isn't making.
Fitted the old Relay back in and she fired up! She's ALIVE!!!!!! Thanks to everyone who pitched in and helped I have learned alot over the last 2 weeks! What a feeling it is when you get it going!
For anyone who is interested here is a bit about the diode that is fitted to many relays : https://www.douglaskrantz.com/ElecFlybackDiode.html
Great news I hope I can report similar good news when I install the “immo off” ecu I just got from Chrisw. So far, replacement antenna, relay, dash and keys haven’t worked, so fingers crossed for me please.
