Well thats what I was thinking. But I could be wrong. Earths are all good. No corrosion etc. All tight.
Well i think ive done right thing but will check again when I have time. Multi meter prongs in black and red wire holes in loom plug. Set to volts. Switch key on. No volts shown. Does this mean no power to plug/connector on loom side. I thought it should so 12v for a few seconds?
Yep, you should get 12v for a few seconds. I don't know which wires you should be checking, but red / black seem logical. I imagine from this connection, it's straight back to the relay, so it would seem strange that you are getting 12v out of the relay and nothing at the fuel pump connector. I'd check both again to make sure you are checking the right thing.
I spotted this thread a day or 2 ago but thought you guys would sort it out. Let's be clear about a few things: A relay that is "chattering" indicates a bad connection limiting the available current to the circuit. The relay switches in and applies the load but because of the bad connection the voltage drops and the relay switches off allowing the volts to rise again, so the relay switches on again, etc, etc, etc... At ignition on the relay gets 12 v supplied direct from fuse 5 in the fuse box. This is comes on a brown wire to 2 terminals of the relay, the coil and the switch. Also at switch on the ECU provides an earth to the other side of the coil, energising it and hence closing the switch contacts. This provides power to the pump, the coils and the injectors. After about 2 to 3 seconds the ECU switches the relay off again and the fuel system will now be pressurised. When the engine is turning, on the starter or under it's own power the ECU receives a signal from the crank sensor so it switches the relay on again and also uses the signal for the spark and injector timing. So normally you will hear the pump prime for a couple of seconds then switch off. If the relay is being switched by the ECU and the pump doesn't run you would hear the relay click at ignition on then click off again 2 or 3 seconds later. So Dee Cee, you need to identify which is the fuel pump relay, the wires to it's base are 2 x brown, a brown/black and a brown/white. The brown wires should both see 12V when the ignition is on. If not check fuse 5. The brown/white should have 12V when the relay points are closed. If not, is the brown/black wire switching to ground. If it is the relay points aren't making a connection and the relay needs replaced. If the brown/black wire isn't switching to earth then the ECU isn't earthed, the ECU is faulty, or there is a break in the wiring. If the relay is closing and there is 12V on the brown white the fuel pump should run. If it doesn't then, the pump could be faulty, the connector under the tank could be loose, there could be a break in the wiring between the pump and the relay, or the pump isn't being earthed (the black wire on pin 4 of the tank connector). A test lamp is the easiest way to check all these. Connect one side to earth and probe with the other for 12V or connect one side to the +ve of the battery and probe with the other for a ground connection. Good luck
Actually, I made an error. When I asked you if Falkirk is any closer to you than Glasgow, I actually meant Forfar. You are a very lucky man, because Derek lives in Forfar, which looking at a map, isn't far from you at all and he is now running a small business repairing and servicing Ducatis! I really wish he lived that close to me... OR
Not so much a business as a hobby to be honest. I don't do Ducati servicing for a living and I don't advertise. I just get work by word of mouth and I also do freelance electrical repairs for a local bike shop.
I did say small business, Derek and are you still sure you can't be persuaded to move to Devon??? :wink:
that will do for me ,, bit busy re work nxt few weeks but may well be in touch soon,,, ( act got a very good friend who lives in Forfar )
Derek's knowledge of Ducatis and Ducati electrics is positively encyclopedic. When I first got my 999, the brake-light switch for the front lever wasn't working. I couldn't work out what was wrong so posted for ideas. the only response was from Derek to say try the connector on the right hand frame rail, just under the front of the tank. I found it, gave it a wiggle and hey-presto - been fine ever since. Derek can also supply and fit Exige's Exact-fit ccw belts and his Exact-Start cables too and do your valves while he's at it. Wish he lived near me... OR
Derek, This bit below I sort of knew but wasnt sure. Having this typed here confirms this. Cool. :smiley: " Also at switch on the ECU provides an earth to the other side of the coil, energising it and hence closing the switch contacts. This provides power to the pump, the coils and the injectors. After about 2 to 3 seconds the ECU switches the relay off again and the fuel system will now be pressurised. When the engine is turning, on the starter or under it's own power the ECU receives a signal from the crank sensor so it switches the relay on again and also uses the signal for the spark and injector timing. So normally you will hear the pump prime for a couple of seconds then switch off. If the relay is being switched by the ECU and the pump doesn't run you would hear the relay click at ignition on then click off again 2 or 3 seconds later" ( If the relay is being switched by the ECU and the pump doesn't run you would hear the relay click at ignition on then click off again 2 or 3 seconds later ) And this is what Im getting. Cheers derek, thanks for the info. Im waiting on a test lamp then im on it. Im not a sparky but find this really interesting. Wanna fix it myself, just for my own satisfaction.
Yes, if the relay click on then off again a couple of seconds later then it is being switched by ECU OK. The fact that it switches implies that there is 12V to both relay circuits, the coil and the switch, since they are both fed from the same brown wire. So either the relay is faulty, but you say you have replaced it with a new one, or the pump is faulty or there is a bad/broken connection between the relay and the pump or the pump is missing the connection to earth.
