Ducati.ms - The Ultimate Ducati Forum banner
  • Hey Everyone! Enter your bike HERE to be a part of this months Bike of the Month Challenge!

1 - 20 of 43 Posts

·
Registered
Joined
·
58 Posts
Discussion Starter #1
Hi, I have a 2001 ducati 748, that has been sitting for a while, not in the greatest of condition. I'm getting ready to part out, but before parting out, I wanted to do a video of the engine running, and get a shot of the engine vin and stuff. Well the other day I dropped a new battery in it, and it wouldn't start. I went through, and checked all my fuses, swapped the relays under the seat, but still have no luck. The pump works when feeding 12volts directly. I should also add, that the ignition has failed on this bike, so I have to hotwire it to get it to start. Although that shouldn't have anything to do with it, because It has been like that for a while and would start fine previously. So, a few questions. I was following this wiring diagram https://www.speedzilla.com/forums/attachment.php?attachmentid=23985&stc=1&d=1255774214 does anybody know where the fuses that are not in the fuse box are located, and would any of the fuses out side of the fuse box, or relays down by the battery have these three things in common? (brights, fuel pump, ignition switch)

Thanks
 

·
Registered
Joined
·
58 Posts
Discussion Starter #2
I found this in the manual

Two fuses on the right side of the rear sub-frame protect
the relays of the injection system (1, fig. 45.2).
The fuse located on a side of the battery (fig. 45.3)
protects the electronic regulator. Remove the fuse cap (2)
to expose it.

So I will check those tomorrow, but I am still hoping someone here can point me in the right direction to what exactly would cause these 3 things to not function.

thanks
 

·
Registered
Joined
·
3,950 Posts
I don't understand the extent of the problem. No electric power to anything at all?

Large main fuse on the right side of the battery tray needs to be checked.

On/off switch needs to be checked.

Confirm that you are getting power to and from the ignition switch (one with the key)
 

·
Registered
Joined
·
58 Posts
Discussion Starter #5
I got headlights, dash, and blinkers, but no brights, fuel pump, and start button. I flip my kill switch back and forth and still get no fuel pump prime. Now you got me thinking that I might just have a faulty kill switch, and the issue with the brights, is non related. My ignition key switch has been faulty for some time, and in the past I would just jump a few pins at the wiring harness to get it started.
 

·
Registered
Joined
·
58 Posts
Discussion Starter #8
wtf does "brights" mean?
High Beams. Maybe it's just a US or California term. You guys don't use the term "flash your brights", or "turn your brights on"? Any ways, I found out the high beams issue was related to the yellow relay next to the battery. My brights(or high beams) now work fine, but I still have no fuel pump prime, and the engine start button does not crank the starter.
 

·
Registered
Joined
·
58 Posts
Discussion Starter #10
side stand down?
The fuel pump should still prime though. This is what is leading me to believe my kill switch is not functioning correctly. I'll take a look at the wiring diagram a bit more and attempt to bypass the kill switch tomorrow.
 

·
Registered
Joined
·
1,429 Posts
I had the same problem on my 996. Bought it not running. I printed a large copy of the schematic and literately "pinged" all wires, relays and fuse connections w/O finding any issues.
Just about to replace the ecu, I found out that the previous owner installed the eprom backwards. I don't know if that fried the eprom, but a new eprom fixed the problem.

Hence, assuming that you bike worked just fine, fuses relays and connections are fine, you didn't swap the eprom while sleepwalking I would remote guess it's either the eprom or the ecu.




Sent from my iPhone using Tapatalk
 

·
Registered
Joined
·
58 Posts
Discussion Starter #14
I had the same problem on my 996. Bought it not running. I printed a large copy of the schematic and literately "pinged" all wires, relays and fuse connections w/O finding any issues.
Just about to replace the ecu, I found out that the previous owner installed the eprom backwards. I don't know if that fried the eprom, but a new eprom fixed the problem.

Hence, assuming that you bike worked just fine, fuses relays and connections are fine, you didn't swap the eprom while sleepwalking I would remote guess it's either the eprom or the ecu.




Sent from my iPhone using Tapatalk
I have a second parts bike. I will try to swap from the parts bike to see if it resolves the issues.
 

·
Registered
Joined
·
58 Posts
Discussion Starter #15
I have a second parts bike. I will try to swap from the parts bike to see if it resolves the issues.

Update: swapped ecu and started blowing regulator fuses.(3amp on the bottom of fuse box). Checked voltage at fuel pump and I got 10volts. I had a similar issue with a voltage drop at the pump like that on another bike, and it was related to a corroded fuse not making a very solid connection. That may explain the no fuel pump, but I'm still confused on why I got nothing when I hit the engine start button.
 

·
Registered
Joined
·
58 Posts
Discussion Starter #16
Taking a look at the wiring diagram again, it looks like the kill switch goes directly through that lower fuse, which may explain the blown fuse and no engine start button, but the main culprit is still unknown.
 

·
Registered
Joined
·
58 Posts
Discussion Starter #19
Ok, another update. I swapped the hand controls and it stopped blowing fuses. Appeared to actually be issues with left hand controls blowing regulator fuse. Now, I still have to figure out why I have no fuel pump prime or engine start button. My fuel pump may be related to the fact I only have 10volts at the pump. I will follow the power with my multimeter and see if I can pinpoint where the voltage drops takes place. I want to try swapping ignition keyswitch, but I have lost my key to my other bike.
 

·
Registered
Joined
·
58 Posts
Discussion Starter #20
So, I believe I measure voltage across the wrong 2 pins for the fuel pump. I've attached a picture of the voltage output for the fuel pump connector. I think the 2 I'm getting power to is for the float sensor, not for the pump. I don't get power to the pump even momentarily when flipping the kill switch.
 

Attachments

1 - 20 of 43 Posts
Top