ignition fuses blowing on tenere 660z
 

my 1.600 mile year 13 tenere 660z .cut out yesterday.it had blown a 10amp ingnition fuse..i replaced it but it blew immediately..the lights all come on and it cranks over fine but wont start...replaced the fuse again this time it ran ,switched on and off 3 more time running ok..then it blew again ...it either runs for a few seconds before blowing the fuse or it blows the fuse immediately...i have checked the battery connections and had a general look around the electrics...the relay was making a click noise before starting when it did start,but i assumed this was normal...the bike has not been altered its as new and well taken care off....no muddy water emmersion ect....any help greatly appreciated

There are quite a number of components take a feed off ignition fuse 4: starter relay (trigger), ECU, start inhibit relay (trigger), engine stop switch, instruments, immobiliser and cooling fan relay (trigger). The ECU, instruments and cooling fan relay are highly unlikely to be the issue, but it could be any of the causing the issue. However�

From what you describe, and the fact that everything works except the starting (and that it�s intermittent) would suggest it could well be the starter relay. This relay is not diode protected so any internal problems, such as quickly collapsing field coil voltage when de-energised, will cause a temporary spike (a �fly back� diode would provide a safe slow leak for the excess current). Fly back current like this can cause arcing and damage to the relay, reverse currents and blow fuses. The arcing can then cause a �sticky� relay contact, which might explain why it works sometimes and not others and is making louder than normal clicking noises?

Best thing to do would be to try and get a known good substitute starter relay and swap with the suspect one and see if the problem goes away. A new relay is about �50, so you�d want to make double sure before condemning the existing one.

thank you very much i shall try source a new one....and fit it..here's hoping

the part is coming in at �59.or i can buy a copy part at �39 from VE off sutton spares same part number ...however the fact that the bike did start two or 3 times and ran for up to 10 second before blowing the fuse ,would this still indicate a relay fault...could the power spike come into play 10 or more second later?....sorry but pretty crap at electrical stuff..cheers

It could. Particularly if the relay's points are sticky it may not be releasing quickly either. The starter relay does a lot more than just the starting too. All the power from the battery goes through it (and the main fuse) and it provides feeds to fuses 5, 6 and 7 amongst a lot of other things such as the regulator/rectifier. So there quite a lot of potential for the starter relay to cause trouble.

However, I must emphasise what I said earlier, that your symptoms "would suggest" the starter relay, in other words, it isn't definite, just very likely to be, which is why "borrowing" a relay would be a good move. It could be any component I have mentioned in the last couple of posts! But the starter relay is what I'd turn to first.

thanks i appreciate your help
...thanks again

My friend thinks it may be an ignition coil...

It could be, it's another one of the multitude of components through fuse 4. It is pretty easy to test the coil if you have a multimeter to hand. A fault causing a short/blown fuse is most likely to be in the low tension/primary side of the coil. However, the fault could just as easily be in the +ve supply wire to the coil making contact to earth.

To test the coil primaries, unplug the connector and connect your multimeter (set ohms not K ohms) across the terminals for the primary windings (low tension) on the coil. It should be in the range of 3.4 - 4.6 ohms.

To check the secondary (high tension) windings, connect the multimeter (set to K ohms this time) between the primary terminal with the red/white wire and the conductor inside the plug cap. It should read between 10.4 - 15.6 K ohms.

And again.thank you..there is a relay from a 2006 XT660 for sale on e bay from a breaker at 15 pounds.do you think this would fit .even as a temp in order to help to resolve the relay functionality question...cheers

By the way I am in the picos in spain currently (not on the bike ..sadly) so I cant try your v helpfully suggestion unroll my return next week.but thanks again.frank