Battery drain on start up

[Davez29]

Ok, I seem to be having my yearly hiccup in the electrics department and was hoping for some direction in this from you lot..

What it is. Last week went to work, left the bike all day and came out 12 hours later, went to start the bike and a very weak battery quickly, within 2 or 3 presses just went flat, no hope of starting it. Luckily carrying a spare battery saved the day and I got home.. that 2nd battery appeared to be charging according to my 3 colour LED on the bike. When I got home I tested the voltage over the battery at 3000rpm and it was within spec roughly 14.5v. I charged both batteries to be sure and all seemed fine according to my optimate.

So, due to working in Newcastle nightshift this week I never used my bike (too dodgy to leave around the streets at night). Today decided to use the bike for work and as usual after leaving it for a few days it was a tad harder to start, but did start, using the battery that appeared to die on me last week. I used the multimeter and the battery was showing a good charge, all is well I thought.

Unfortunately I then noticed I had no front lo beam lights, high was ok.. I wiggled wires, clicked switches but nothing.. So decided to check the bulbs, all looked fine but on restarting the bike the same symptoms as last week, dead within a press or two??? So not sure why it was happening and thinking a dodgy battery put my other freshly charged spare battery on.. within 2 or 3 presses that was drained, wtf.. I did note on the multimeter that both batteries went down but recovered upto 12.7v after a couple of minutes but trying again they just died quickly.

Batteries keep charge on and off the bike, as long as I dont turn the bike on (key only), turning the bike on (key only) the batteries quickly dip in power and continue quickly draining and I dont even have the front light on, which are usually permanently on.

So far I have checked, fuses, charging volts over the battery. Amps leakage, wiring around reg/rec, wiring around stator plug under the tank. Will do the multimeter bits on those items tomorrow, after work. I just changed the pulse coil for a new one just in case this had a bearing, no change.

Things I have done to the bike which may have a bearing.

lo beam mod at least a year or so ago but no front lights now (checked inside left switch Hi/lo and appears fine)
New Stator coils 6 months ago ish.
Reg/Rec 6 months ago ish.
Pulse coil (just changed as a precaution).

to sum up..
No front lo beam.
Batteries draining as soon as bike is turned on, leaving a couple presses of decent power at the most.
Charging seems fine once started, if it does start.

Help!!

[thunderace]

Try replacing the low beam relay, it may have fused across the coil causing a short.

[Davez29]

Thanks Thunderace, I see, so will be replacing as soon as possible. I did think there's something up in this area but im no expert. just a couple of month ago i was blowing lo beam on my bulbs so maybe it was a warning of something up. Although that did stop when i located the relay more securely.. Will see how it goes and report back tomorrow night.

One thing though, would this not show on the amps test, as used in Haynes? (then again maybe not as the ignition is not turned on for that test, as only with power does my battery drain).

cheers

dave

[thunderace]

When you replace the relay, use some heatshrink tubing over the crimp connectors and then a larger piece to enclose the whole relay if you can. Best to try and keep it as waterproof as possible

PM me your address and I'll send out a relay and some heatshrink on Monday

[Davez29]

Thank you sir. PM sent

[Davez29]

Ok, I decided to see if it was that damn mod I done so took the relay out, all looked fine and to really check and in the interests of science I broke the relay apart, no burning or anything, looked fine. So I disconnected all mod wiring and put the wiring back to oem, tried again but still draining fast. No change and not starting either.

Amazingly after ages I managed to start the bike after several recharges but noticed an almighty "crack" from the starter solenoid as it started. The bike warmed up and idled fine and charging was fine. I also disconnected and ran the bike without the reg/rec all fine I managed to do tests to the alternator volts were around 50v. Thinking Im lucky I stop the bike to see if there is a change after that solenoid crack, nope the same draining fast, around 10th volt a second and then when pressing the starter, battery drains below 8v immediatly but amazingly recovers to 12.7 volt quickly once i turn the ignition off.

I have checked alternator, resistance all fine. I have checked reg/rec all fine.

While doing all this I pulled the front bulbs but forgot to check if they are back on after my mod dissection. will check tomorrow.

Im now leaning towards solenoid or even the starter motor, not much left i suppose.

Im stuck!

[thunderace]

Hmmm, could be the solenoid then. I've only got a couple of universal ones that need the loom connectors modifying but they're spoken for or I'd have popped you one out with the other bits.

[Davez29]

no problem. will get another from ebay, no doubt they are crappy but hopefully i can test for problems. BTW all wiring looks fine but I will clean all contacts.

Could my starter motor brushes be on the way out, would I get that sort of problem or would the starter just stop working?

[thunderace]

The starter would just stop working. It could even jam if the remains of the brushes fell into the core housing.

[Davez29]

Ok.. Maybe starter aint a problem then. It certainly seems ok. Im just looking at all angles.

Didnt have time to do much today but the bike started fine several times with full charge. Just waiting for the solenoid to arrive.

One thing, would anyone be willing to try a quick test using a multimeter on a normally fine bike? What i need is someone to pull their front lights, so just instruments and rear light are on. Now turn the bike on (key only) now tell me how quick your battery discharges over a minute. Currently im losing 0.1v a second. Now start your bike and tell me what voltage it drops too while using the starter, mines is going down to 8v. I need a simple benchmark as i could be wrong .

Cheers and thanks for help so far thundeace.