Battery neg lead playing up

[crazywakey]

Hi chaps,

Looking for a bit of advice here - my R1150GSA is being a bit naughty at the moment. Sometimes it will fire up straight away, others it will give me the impression that the battery is dead. I've had the fault for some time now, but because I can apply a "temporary fix" (take off the seat, fiddle with the battery lead until the circuit is good then hit the start button!) I've not done much about it. It's starting to nark me now though. I've just replaced the battery with a MotoBatt 4 terminal jobbie, as the old battery wasn't holding a charge so well anymore.

Anyhow, I know it's the neg term lead that's an issue. Has anyone come across this before? I know the term lead is part of the whole cable harness, and don't want to go to the extreme and cost of replacing the whole wiring loom - it's a 12 year old bike at the end of the day, so I'd rather know if there's anything I can do first?

I shall check the connection again when I get home today from work (as long as it gets me home!), but I think it's actually the battery terminal lead itself and not the physical connection at the terminal.

Good advice gratefully received!

 

[Fanum]

Go to any motor factors, car place or even Halfords, and buy a generic bike battery earth lead.

Or (what I did) make one up....I used a couple of feet of old booster cable with some heavy duty crimp terminals.
Run that from the battery terminal to the starter motor mounting bolt (or even just whack a booster cable on, clipped directly to the battery terminal to the starter casing) , and try starting the bike.


If that cures the starting issue, it will still be worth replacing the original item.......if it's degrading more and more, it could eventually cause you other problems.

 

[Ian J Hartley]

The heavy current earthing is done through the engine casing.

The battery high current negative lead is about 40cm long and runs from the battery negative terminal to a ring terminal on a stud on the engine casing located under the battery tray. The ring terminal which is crimped and soldered has all the negatives leads coming off it which feed out into the loom.

It might pay you to examine where this ring terminal connects to the casing. It could be corroded and giving a high resistance between the battery and the casing. it doesn't take much of a resistance to drastically reduce the voltage when high current is flowing.

Ian

 

[crazywakey]

Thanks guys

Been digging around with it this afternoon.... I reckon my first problem is that the new battery has funky bolt-on terminal brackets that might as well be made of pasta for the effectiveness they provide - too small and awkward. Anyway, I've gotten around this with some funky bracket building from bits and bobs, but it seems in the process of all this, my new battery has lost it's juice. It's now on charge overnight, will see how it starts tomorrow. Will also check the other end of the earth lead as you said Ian. Tried the booster cable trick Fanum but with the batt so low, it didn't have the will-power.

Cheers for the help guys!

 

[Packer]

+1 for checking the earth terminal to engine housing under the battery tray. A bit oif a faff getting to it but mine was in a bit of a mess and would have soon been causing many issues if I hadn't sorted it when I did.