750 Paso Wiring Upgrade to Improve Starting
Posted: Wed Jan 26, 2005 2:15 pm
I have finally figured out how to place the upgrade instructions on the web. This is a PDF file that will open in a new window. To just download it directly, just right click the link below and use the save target command. You can download it here:
NEW VERSION!!! Click HERE -->> Upgrade Instructions Rev2 (11/25/2006)
As some of you know the Paso has very unique way of protecting from theft. If you don't know about it's electrical quirks, you can't get it started. The colder weather has only made this condition worse if that's possible. In the colder weather it just won't crank over. One solution is to use the kill switch to remove the ignition load as you get it cranking. Once the starter has the engine turning over, you flip the kill switch to the "ON" position for spark and the engine catches.
An hour spent with a voltmeter and the wiring diagram (oh such Saturday fun) revealed the following:
Battery 12V
Feed to Fuse Panel 10V
Coil Feed 9.2V (25% loss!!!)
The voltage drop from the battery to the fuse panel is caused by the route that the power takes. The full electrical load is switched by the ignition (key) switch at the head stock. Along the way it goes thru 6 plugs/connectors and drops at least 2 volts. The fuse panel is 6 inches away from the battery, so why they run the juice thru about 14 feet of wire on the round trip is a mystery only the engineers at Ducati understand. I cleaned all of the plugs, contacts and the ignition switch to the best of my ability to little positive effect. The only way to resolve this problem is to install a relay to switch the power on and off near to the fuse panel. I did this today (following directions posted here) and I now have only a 2/10th volt drop in the system: 11.8V and the fuse panel and the ignition switch now only operates the relay instead of all of the current for the bike. After the system relay install, the coils were still quite low in the voltage department, with an improvement to 10.2 (from 9.2) volts mearured at the coil.
The solution to the low voltage is an easy one! Just throw in another relay. I ran a feeder from the fuse panel to a relay at the coils and fed them that way. By using the stock coil wiring to switch the relay, the kill switch functions normally. The voltage at the coils is now 11.8V and the spark will be much STRONGER particularly when starting cold.
I was going to put in a relay for the headlights but now I'm not sure if it's necessary. I thought that the headlight being on during starting was the cause of the intermittant "No Starter" condition but it was actually the system voltage drop and the coil load that was keeping the starter solenoid from engaging. This work took about 4 hours to do and is very easily reversible and looks quite stock.
Cost: $5 for some Bosch Relays ( I had some laying around), crimp on type connectors and some wire.
NEW VERSION!!! Click HERE -->> Upgrade Instructions Rev2 (11/25/2006)
As some of you know the Paso has very unique way of protecting from theft. If you don't know about it's electrical quirks, you can't get it started. The colder weather has only made this condition worse if that's possible. In the colder weather it just won't crank over. One solution is to use the kill switch to remove the ignition load as you get it cranking. Once the starter has the engine turning over, you flip the kill switch to the "ON" position for spark and the engine catches.
An hour spent with a voltmeter and the wiring diagram (oh such Saturday fun) revealed the following:
Battery 12V
Feed to Fuse Panel 10V
Coil Feed 9.2V (25% loss!!!)
The voltage drop from the battery to the fuse panel is caused by the route that the power takes. The full electrical load is switched by the ignition (key) switch at the head stock. Along the way it goes thru 6 plugs/connectors and drops at least 2 volts. The fuse panel is 6 inches away from the battery, so why they run the juice thru about 14 feet of wire on the round trip is a mystery only the engineers at Ducati understand. I cleaned all of the plugs, contacts and the ignition switch to the best of my ability to little positive effect. The only way to resolve this problem is to install a relay to switch the power on and off near to the fuse panel. I did this today (following directions posted here) and I now have only a 2/10th volt drop in the system: 11.8V and the fuse panel and the ignition switch now only operates the relay instead of all of the current for the bike. After the system relay install, the coils were still quite low in the voltage department, with an improvement to 10.2 (from 9.2) volts mearured at the coil.
The solution to the low voltage is an easy one! Just throw in another relay. I ran a feeder from the fuse panel to a relay at the coils and fed them that way. By using the stock coil wiring to switch the relay, the kill switch functions normally. The voltage at the coils is now 11.8V and the spark will be much STRONGER particularly when starting cold.
I was going to put in a relay for the headlights but now I'm not sure if it's necessary. I thought that the headlight being on during starting was the cause of the intermittant "No Starter" condition but it was actually the system voltage drop and the coil load that was keeping the starter solenoid from engaging. This work took about 4 hours to do and is very easily reversible and looks quite stock.
Cost: $5 for some Bosch Relays ( I had some laying around), crimp on type connectors and some wire.
))