It wont start ??

[Commadore]

I'm after advise please:

My 2006 R1200GS will not start, turn the key and all the lights come on as usual, usual faint whirr of the petrol pump for a second or two. All computer checks ok with no warning lights.
Bike is in neutral (checked by hand turning the rear wheel as well as the dash indication), side stand is up, clutch has not been pulled prior to start. Kill switch is in the central (not kill??) position.
Press the starter button, faint click heard from the starter relay beneath the seat but nothing else.
Tried testing the battery, voltage about 12.5, which does not drop when the starter is pressed.
Have had the starter motor out and bench tested it and it works fine out of the bike, solonoid doing it's bit, all ok.
There is 12.5v to the starter, and when the small lead to the solonoid is taken off and tested, there is 12.5v to that when the start button is presses.
However, when the small lead is connected to the soloniod and the start button is pressed there are no volts.....

I have tried jump starting the bike. This does not work when jumping via the battery, but if I attach the jump leads to the starter motor soloniod it kicks into life and the engine starts?

I'm confused and running out of ideas? anyone help please?

 

[littleredrooster]

I was going to say 'flat battery', but that does not fit with this:

...Tried testing the battery, voltage about 12.5, which does not drop when the starter is pressed.

It seems to rather point to the starter relay, as the battery voltage should drop slightly when under load. The fact that it's not dropping would suggest it's not being put under load.

..and just re-read the symptoms - no voltage on the energising wire to the solenoid points again to the relay. Got a mate you could swap relays with?

 

[Pukmeister]

It sounds like the internal secondary contacts inside the starter realy have failed, its obviously energising the primary coil and making a click.

The fact there is no volt drop across the battery when engaging the relay shows it is not drawing current from the battery. I would expect to see a noticeable drop in battery terminal voltage as the starter draws current.

Also 12.5V is a little on the low side of fully charged for your battery.

If you know which are the 'high current' secondary contacts of the relay, you could briefly bridge the corresponding contacts of the relay socket to energise the starter motor (hot wiring).

The fact it spins when putting the jump lead onto the starter shows the starter motor is not at fault nor is the main feed cable or battery, the solenoid is simply not receiving any volts from the relay.

Easy to prove: Disconnect the small wire going to the starter motor solenoid, connect your meter across it and the battery negative terminal, press the starter button and you should see a +12V DC signal on the wire. If not, the relays fecked.

 

[autogs]

sound advise from pukmeister,
the relay is under the tool tray i think,if i can remember my 2006 gs days.

 

[Commadore]

That was indeed sound advice....save for the one small detail, that being that when not under load the relay works fine.

Anyway, Many thanks for the help. Turns out, after much testing that the problem lay in a corroded live wire to the relay. This was down to one small fibre as a connection - hence the symptoms described.

Small rewire and all sorted.

 

[Pukmeister]

Glad it's sorted, a few owners of the earlier 1200's had a similar problem with corroded wires on the relay socket wiring.

Did you check the wires going to the back of the accessory socket for corrosion whilst you were at it ? My guess is they are probably a green mess of copper and verdigris by now.