sudden electrical short please help

I have an 82 xj650 maxim. It has been sitting for a while. everything was fine when parked. I tried to start it
a couple of days ago. Turned the key, neutral light went on, horn was faint. Pressed starter button and the starter sputtered with not enough juice to spin the motor. So I put my battery charger on it set to 10 amp
quick charge and left it for a couple of hours. When I tried to start it I got nothing, no horn, no neutral light
and whenever the key was turned the signal fuse would blow. I figure the battery was toast so I replaced it.
turned the key and signal fuse blew again. Not being able to find short glass fuses in my area, I replaced the
fuse block with a small after market fuse block taking auto fuses. Got everything together and the same thing,
the signal fuse blew. Can anyone suggest circuits or relays to start testing ? Could the 10 amp charger have melted or shoted something ?

 

I would open up the headlight bucket and look for evidence of critters chewing on wires.

 

no critters in my garage

 

Check if you have any damaged wiring touching the frame, and corrosion on harness wiring in electrical plug connectors.

 

many years ago I had a girlfriend riding an FJ600.
The bike kept blowing fuses, always good in the garage but always reoccurring when out riding.
The wiring harness was worn where it rubs on the steering neck.

 

Same thing happened with my Suzuki GT 250.

Same thing happened with my Suzuki GT 250.

 

Great suggestions, I couldn't figure why I don't get horn and neutral light when the key is turned on and why the signal fuse also blows
when the key is turned. Could that be happening because a wire in the signal lighting system is grounded ? I was thinking of just stripping the harness, fastening it
to a sheet of cardboard, first look for damage then check each circuit for continuity and resistance. also check all the relays. Funny though because neutral light
and horn worked at first but the battery was too weak for the starter to turn the engine over, so I hooked the charger to it at 10 amps for a couple of hours. thats when
something fused or melted.

 

Check the wires from the components that are not working. I always start at the components that are not getting power and check the wiring connections for corrosion causing high resistance all the way back. Follow the wiring diagram and check each connection with a multimeter. You can also pinpoint physical damage that way where a wires insulation may be damaged and the wire is shorting onto the frame etc.

Check the wires at the signal mounts where the units bolt to the frame. You don't need to strip the harness chances are the problem is not in the main harness which is taped up from the factory because those wires are better protected. Check also the indicator bulb holders for any signs of corrosion.

 

You didn't charge the battery the wrong way did you? It is possible, and would fit in with your symptoms. Get a dvm across it.

 

I may have hooked it up to the charger at 10 amps with the key on. I think I may have fried something. any Idea what devices may have been damaged ? I have lots of extra parts.

 

My guess is you don't get along well with signal fuses, perhaps one of these threads will have your answer

https://www.xjbikes.com/forums/threads/xj750-blowing-the-horn-signal-fuse.117250/

https://www.xjbikes.com/forums/threads/blowing-fuse.53939/

I assume they were both eventually fixed?

 

Do you have a wiring diagram for it? If not get one. Then start by disconnecting various items, as many as you can and then switch on. One by one start connecting stuff back in.

 

Yes I do,I'm working on two bikes now. An 82 maxim (blowing the signal fuse) and an 82 seca which has horn,neutral light and signals when the key is turned but no starter button. thats why I was
testing the relays. I bypassed the cutoff relay by jumping the two red/white wires at the relay terminal. the button now spun the starter, I checked for spark, had spark, so I fed fuel to the carbs via
aux. bottle, applied the enrichment,. pushed the start button and it ran for ten seconds and then died. No start button again even with the red/whit wires jumped .