Starter cut-off & fuel pump relay - loose earth
 

Hello all,

The bike (2010 XT660Z) cut out totally the other day. On trying to restart, the instruments and instrument lights blink on and off as though there is a loose connection, there's a screeching noise from the starter cut-off/fuel pump relay unit and you can hear one of the relays clicking on and off.

Removing the relay removes the problem with the instruments/instrument lights but obviously the bike won't start without the relay.

Replacing the relay unit seems the obvious option here (the bike has 60k hard miles on it) however looking at the male plug that goes into it, there is a loose earth wire in addition to the one already in the plug. There should only be one earth wire, so I'm at a bit of loss about what this second one is doing here and whether this has anything to do with the problem.

Any ideas?

Photos below, along with a video of the original problem as described here.

Photo of spare earth wire
Photo of relay wiring chart

Thanks in advance

Ed

Before you go pointing a finger at anything expensive, are you sure the battery is fully charged? A weak battery will cause all the exact same symptoms as you describe. Also is the engine trouble light flashing any codes at you?

Check the battery first, then get back to us.

Hi Pleiades

Thanks - the battery is fine. Nothing from the engine trouble light.

Ed

OK, so we can rule out the simple stuff.

As for the main/starter relay, you can test it if you have access to a multimeter. You will need to remove it from the bike, make sure the fuses are still intact and then first test the resistance of the relay's coil by connecting the multimeter across the red/white and blue/white wire's terminals. It should have a resistance of between 4.18 and 4.62 ohms.

Next test the continuity between the terminal that goes to the starter and the one the feeds from the battery; there should be no continuity (infinite resistance). Whilst the multimeter is still hooked up apply +12V to the red/white wire terminal and the negative to the blue white wire. The relay should click (latched) and there should now be full continuity on the multimeter display (0 ohms).

If any of the above is out of spec or does not give the desired result, then the relay will need replacing. If the relay passes the tests, then further investigation of the connectors and wiring should be the next port of call.

As for the 'spare' earth, I'm not sure. It might be normal? I'll have a look at mine and see what it looks like as I can't recall off-hand.

Great, thanks Pleiades. Will check this out further.

Ed

Before you go too far, just check your battery terminals aren't loose.

I had this problem myself - turn ignition, everything fine. Hit start and everything died. You had to turn the bike off before you could try it again.

My ground terminal was loose, took me 1 min with a screwdriver to fix it.

How did it go? I have some of these symptoms myself but have no clue what to do. Tried a brand new relay... Same thing.