Coil relay mod adjusted for 906

discussions specific to the 906 Paso
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romus
Posts: 135
Joined: Wed Mar 25, 2009 12:06 pm
model: 906 Paso
year: 1990
Location: Brisbane, Australia

Coil relay mod adjusted for 906

Post by romus »

I am posting this in case it is useful for 906 owners doing a coil relay mod. I did mine by referencing the '750 Paso Wiring Upgrade by Jonathan Slocum' which explains the mod for the 750 and 'Engine Feed Relay by David Hooau' which applies it to the 906 with a few complexities that I avoided.

I have been installing a new wiring loom so did this job as part of the process. I am sure if I have made a mistake others will offer feedback and I can edit this. The bike goes :-)

As per the 906 wiring diagram the coils are fed by the red wire coming from the connector on the right side by the seat. This wire can be cut and connected to a new red wire that feeds to the relay. In this picture I have done that, so my finger is on the wire that was cut that still goes to the coils. I shrink wrapped it. The wire by my thumb is connected to a longer red wire that goes back to a relay. I used 5mm 25A wire.

Image

The red wire from the connector now connects to 86 of the relay:
Image
NOTE: Some relays have the fixing point as if this picture is upside down, but the position of the tabs on the relay and numbering is the same.

30 is connected to the Starter Solenoid at the point where the other red wires are attached. This wire has an in-line fuse (I've put in a 20A fuse):
Image

85 is earthed:
Image

The wire from 87 on the relay is fed to the horizontal coil and from that point a wire connects to the vertical coil. That is the same as the original wires (which I disconnected and shrink-wrapped:
Image
P.S. The coils are the dc3-1's from Dynatek.
Warwick - on a learning curve and on a
Ducati Paso - Soul of a thoroughbred :P
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paso750
paso grand pooh-bah
Posts: 5558
Joined: Sun Jul 18, 2004 12:00 am
model: 750 Paso
year: 1987
Location: southern Germany

Re: Coil relay mod adjusted for 906

Post by paso750 »

There`re different places you can add a relay. Yours impacts only the voltage to the coils which is of course absolutely fine.
It can also be placed in the return line of the ignition switch (but not everyone will be willing to cut the main power lines). In this case also the lights will benefit.
Derek wrote:Since I've had my 907 all the lights on the bike, including the headlight, were varying in intensity slightly in time with the indicators every time I used them. I went round all the earth connections, then the battery positive connections and eventually found that it was dropping over 1V across the ignition switch when the headlights were on.
To sort this I fitted a 30A relay close to the fuse box and cut the brown return wire from the ignition switch that normally goes to the fuse box and connected it to pin 85 of the relay, adding an earth to pin 86. I took a Tee off the thick red wire from the Fusebox 25A fuse that goes to the ignition switch and connected that to pin 30 of the relay. Pin 87 was then connected to the other side of the cut brown wire connecting it to the fusebox for the switched circuits.
So that now when the ignition switch is turned on the relay switches and output from the 25A fuse is connected directly to the input side of the 15A fuses via the relay.
No more blinking lights and the headlight is noticeably brighter. The ignition switch no longer has a heavy current to deal with and should last much longer. :)
http://forums.ducatipaso.org/viewtopic.php?f=2&t=6422
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ducinthebay
paso grand pooh-bah
Posts: 1323
Joined: Sat Sep 03, 2005 12:00 am
model: 750 Sport
year: 1990
Location: SF Bay Area

Re: Coil relay mod adjusted for 906

Post by ducinthebay »

Nice post. Thanks,
phil
Duc in the Bay
1990 750 Sport x2-Rosso Blanko (900ss copy) & Nuovo Nudo (Scrambler project)
1991 907 -mostly stock
2002 ST4s - Lots of mods.
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