Fuse blows when connecting right coil

[Guest bordsenius]

My V11 gave up on me 23 May. The 10-amp fuse for the injection/coil/fuel pump went. After 3 months, the motomania-shop here in Oslo simply gave up ,and I had to pick the bike up with a trailer at the back of my car. I was quite annoyed at this, needless to say.

 

So now it is in my garage, and I am trying to figure out what is wrong. After some fiddeling around I have found out the following:

 

If I disconnect the right coil the fuse does not blow. Everything else on this circuit is connected. I have tried to connect the right coil wire to the left coil, and the fuse blows. I have connected the right coil on the left side(replacing the left side coil), and no coil on the right side, and the fuse does not blow. I have disconnected the injectors as well. So the problem is not in the coils or the injectors. It is somewhere else.

 

 

Does anyone have any good ideas here? I have replaced all the relays a few years back with good ones from Dan Prunski, and all connectors are sprayed with anti-oxidant spray as well.

 

 

I also need to know how to pick apart the connector for the coil. Is is a black connector with two pins inside ,and some red and yellow plastic at the end. I have gotten the colored plastic off. I know the pins may be extracted without destroying the plastic, but how? Where hould I insert my tiny screwdriver ??

 

 

Stig Bordsenius

[Alex-Corsa]

I also need to know how to pick apart the connector for the coil. Is is a black connector with two pins inside ,and some red and yellow plastic at the end. I have gotten the colored plastic off. I know the pins may be extracted without destroying the plastic, but how? Where hould I insert my tiny screwdriver ??

Stig Bordsenius

 

A few pics could help,

 

I have tried to connect the right coil wire to the left coil, and the fuse blows

I have connected the right coil on the left side(replacing the left side coil), and no coil on the right side, and the fuse does not blow

The solution lies here but it is confusing to me how it is writen. It seems to me that the problem is to the left coil since when you switched the coils connection ,with the same cable, it worked , so it was not the cable.

[callison]

I think you ought to hold off on taking things apart long enough to try something less potentially damaging. To digress a bit, about 30 years ago I overhauled a bunch of radio receivers and I used Cramoline on the contacts because that was what I learned to use in the maintenance class. After a few months of operation, every single one of the receivers I used the Cramoline on failed in use. The ones I hadn't "improved" didn't have a problem. I think you should start with clean connectors. Fill a small jar with alcohol and dip the connector in it for a while, then shake it out an let it dry. Since you're only having problems with one side and only when the connector is engaged, I'm hazarding a guess that there is some contamination and pressure on the connector allows it to be more conductive. Cleaning it out may cure the problem an it may not, but at least it is a non-destructive approach that can be tried first.

[Cliff]

The coils/injectors share a common +12V that is fed by the fuel pump relay.

The other side of the coils is pulled to ground by the ECU. This is normally only done briefly when the spark is required as each coil is only 0.7ohm and hence will draw over 10A.

 

I suspect either a dud ECU is pulling the coil to ground or you have a short to ground on the harnessto that coil

[Paul Minnaert]

I suspect the ecu, No one in your surrounding that has one you can try? You have a v11 with or without lambda/kat? I do have an ecu I will sell.

 

If you disconnect the right coil, does the bike start on one cilinder?

[Guest bordsenius]

Here is a shot of the connector. I know it is possible to get the metal conenctor inside released, this is what I want to do.

 

 

I suspect that the green-black wire on the picture is grounded , and want to check this out.

[Guest bordsenius]

I suspect the ecu, No one in your surrounding that has one you can try? You have a v11 with or without lambda/kat? I do have an ecu I will sell.

 

It is a V11 2001 without a catalyzer. Unfortunately I do not know anyone that has a V11 sport, I don't know if they sold more than 4-5 of them here in Norway. But I am interested in a spare ECU if mine is broken. But just make me make sure that the error is there first!

 

If you disconnect the right coil, does the bike start on one cilinder?

 

The bike is is about 1000 pieces, but if I do not manage to figure this out in a few days I'll try to assemble it without the righthand-side coil connected. But as it takes me about 3-4 hours to assemble it I'll see if I can find some other solution first.

 

The plan now is to replace the wire going from the right-side coil to pin 14 on the ECU. It's just a stab in the dark, but fortunately a very cheap one!

 

I have tried to find out what the behaviour of the ecu should be like, but I have not found a good description. Should pin 14 be +12 V when the ignition is on and the bike is not running?

 

 

Stig

[Paul Minnaert]

You can measure resistance on the green wire before changing. If you unplug the ecu, there should be no resistance on the wire( between the wire and the ground), and for all checks, you can compare right and left measurments. If the wire is shorted you can measure it.

 

Taking the connector out can be done, but if you are not very shure that's it, don't. Parts from this connector are hard to get, and the connector on the other side of the wire, the ecu one isn't available at all. You can not easy put a new wire in. Worst case you need a new wire loop.

[Guest bordsenius]

You can measure resistance on the green wire before changing. If you unplug the ecu, there should be no resistance on the wire( between the wire and the ground),

 

 

If I disconnect both ends of the wire, I would expect it to be infinite resistance between the green wire and the ground as they are not supposed to be connected? Or have I misunderstood?

[Guest bordsenius]

First of all: Thanks to everyone who has helped me out! Your tips pushed me in the correct direction.

 

I started to measure the resistance for the cab le that lead to the coil, and there seemed to be a short circuit. So I started from the ECU, and opened all cable casings. And guess what! The entire cable, with about one zillion wires inside was melted for about 30 cm (one foot) Everything stuck together in a plasticy mass. It is a wonder the bike did not catch fire..

 

 

So tomorrow I'll start removing the bureed plastic and wires , and replacing it with new wires.

 

 

One question arises: Should I exchange all wires, or just the ones that are clearly melted? Could the heat affect the others, making them brittle and possibly giving me a hard time in the future?

 

A sneak peak of the electrical barbecue is attached..

 

Stig

[Tom M]

If I were in your spot I would scour the junkyards/recyclers and ebay for someone parting out a crashed V11 and change out the whole harness rather than trying to repair it UNLESS it was miraculously available new for a reasonable sum from

[grossohc]

Isnt there an American guy parting out a crashed V11 on here, maybe if you do a search

[big J]

Or try Reboot guzzi spares.

[Guest Gary Cheek]

It shouldn't be too hard to splice new wires into the damged area. A new harness would be ideal but carefully done a repaired harness may be easier and less costly. Uninsulated barrel connectors can be crimped and soldered if you like, tthen covered with a section of quality heat shrink tube. Just stagger the splices so you do not wind up with a hump in the harness!

It may be a good idea to investigate the other circuits involved for a possible short. There is a good chance the dealer did the damage by putting a too fat fuse in line while attempting "repair".Ecpecially since you do not recall "letting the smoke out of the wire" Usually when the PVC melts, those around are aware, even on when coasting to a stop on the open road.

 

I futher wouldn't be surprised if that wasn't a factor in them wanting it gone!

[Cliff]

Ouch Stig.

 

The fact that the melting is near the ECU indicates the problem is likely with the ECU and not a short to ground in the harness.