some kind of short

[hadaveha]

i have a 1980 gs850g lately its been of and on dragging the starter, off and on with a very good hot battery, here is the tricky part if i plug a battery tender up it shorts out the tender i have killed 2 tenders, i have never ran into this situation before any ideas

[rphillips]

Ideas?? Like you never heard of such a thing... Can't imagine how a dragging starter could be related to battery tender. Also don't see how a bad battery could mess up a tender, too much safety stuff made into them. Hoping we both can learn something here.

[Brendan W]

I would have thought that tenders have short cct protection on the output.
What tenders were they and how much current?
Ideally you charge at C/10 which means one tenth of the battery capacity.
For an 850 with a 14Ah battery that would be 1.4 Amps.
What do you mean by dragging on the starter?

[hadaveha]

the starter will bump bump spin and then bump gives every indication youd look for in a bad battery how its closing the circut on the tender is baffling to me

[rphillips]

OOhh, bump bump "spin". The "spin" is never good. The gear on the starter is engaged with the gear on the starter clutch all the time, not like a car where the starter gear is pushed into the starter ring when start button is pushed. That seems to indicate a starter clutch slipping on the crankshaft. Still seems nothing even close to a battery tender... Of course just my opinion.

[hadaveha]

i dont think im explaining it right its click click then spin the engine over i ment to say sorry for the confussion any chance i have a short with in the solenoid

[Rijko]

i had a bike on a trickle charger once, forgot to unhook the it and started the bike.
The charger did not like that, going by the smoke was coming off it

[Rijko]

click click spin is usually cheaper to solve than bump bump spin

Unplug the green/yellow from the solenoid and measure voltage on the female connector on the harness when you press start.
Too low and the solenoid will have issues.

With ignition off : take the green/yellow wire of the solenoid and push it against the pole that the big red wire coming from the battery is connected to.
Does that spin the starter differently than using the starter button ?

[rphillips]

Sorry I misunderstood. click click then spin the eng. OK can be the solenoid or possibly starter. How often does this happen. If happens regularly you can check it by bypassing the solenoid, not that easy if just rarely happens.. Still nothing related to tender that I can see.

[Rijko]

Have you tried taking the battery out of the bike for charging ?
That takes the bike out of the equation.

[hadaveha]

i have actually tried more than 1 battery battery chages disconected from the bike just fine

[hadaveha]

I will try the yellow wire test tonight

[KiwiAlfa156]

Clicking of the starter relay with sluggish or no spinning of the starter can be due to a bad ground on the starter relay. The relay mounting strap is the ground and its electrical connection to the negative pole of the battery is indirect. To test make up an earth wire connecting the mounting strap of the relay directly to the battery -ve post. See if the thing cranks properly

[Brendan W]

... and it can also be a bad ground cable return from the crankcase to the battery negative.
A quick check here is to measure the voltage drop from the crankcase to the battery negative when cranking.
Ideally, zero. Acceptable tenths of a Volt