77 XS 400 won't start

[Joshwuh]

2 days ago I left the key in my 1977 XS 400 and the next morning the battery was dead. This is the second time I have done this in a month and the battery was supposedly replaced last year. I bump started it and drove around running errands (when I turned it off I just had to kick start it and it would fire right up). I was driving through town when the bike just shut off completely. I pulled over and nothing was working no electrics and it wouldn't bump start either. Tried jumping it from a guys truck while it was turned off but he put the black plug onto something that wasn't the black battery terminal and it started smoking at the connection. Brought the bike home and tried jumping it from a car and no lights even come on. I think the "Main" fuse might be blown we are going to replace it immediately. This is my first bike and I don't know much about repairs etc can someone please help me or guide me in the right direction to get this running? It is currently my only means of transportation so I could really use some help. Thanks everyone.

 

[FUBAR]

sounds like you answered your own question.
check the fuses, and if the battery is old its possible it cant hold a charge any more and the alternator couldnt keep up with all the electrical on its own so the bike died, then you might have shorted somthing when you boosted it

 

[Joshwuh]

I replaced the fuse and nothing happened but that was expected because the battery is most likely dead. I then tried to jump it from a car (turned off) and still no lights or anything. I then disconnected the jumper cables and tried a trickle charger just to see if I could get lights or some kind of reaction and nothing. After I unplugged that I noticed the new fuse I had put in (the "Main") fuse was blown again. I bought the bike a month ago and have driven 1,000 miles with no major issues. The previous owner told me he replaced the battery last year. However, I took the battery out and the fluid in 4/6 cells was below what it should have been. Some cells were extremely low and others were just barely. Do I refill these with water?

The battery is currently out of the bike and on a trickle charger and I wasn't sure whether to put it on 6 amps or 12 amps. Once the battery is charged I will plug it in and try to start it again (with another new fuse). If no lights come on with the charged battery what other things should I look at to help diagnose the issue?

 

[HoughMade]

Hopefully uou mean 6volts or 12 volts- use 12 volts. It should charge at no more than 2 amps. I would guess the fuse blew with trying to jump it with a car- too much power. The fuse boxes often get unrelaible with age- loose connections. If you continue to have trouble, I would turn the key on and wiggle the wires going in and out of the fuse box. If you get lights to flash on with the wiggling, you've found the trouble.

 

[Joshwuh]

***UPDATE***

Upon further inspection I noticed that the wires going to the battery (black/red and positive/negative) are reversed. In the picture the red wire on the right goes to the crank case and I believe is the grounding one aka usually black colored and the left wire (with the bronze circle) goes into all the wiring of the bike aka is usually red colored. I'm not sure if this is a correct observation but if it is it may have caused more issues because both times I tried to jump the battery from a car I attached red on red and black on black which would mean that I had them backwards. If this was the case can it cause any serious damage.

Although, this is a potential issue it is one that occurred after the initial breakdown so I could still use help diagnosing both of these. The alternator suggestion sounds like a promising diagnosis, especially since the battery cells were low on water, however, I won't be able to try it again until tomorrow morning when the battery is fully charged.

One last question: At the top of the picture my dad is pointing to a wire, can anyone tell me where that goes and what it does. Initially when I attempted to jump the bike the first time I plugged the black jumper cable onto it mistakenly, and that was when it sparked and started to smoke. Should I be worried?

Thank you in advance for any help and information.

 

[Joshwuh]

I did mean 12 volts and thank you for the advice. I have it set on 12 now. I will try to wiggle the fuse wires tomorrow once the battery is fully charged. Thanks for the tip!

 

[FUBAR]

those blue wire crimp/splices look suspect coming off the red wires connected to the fuse box...

 

[Joshwuh]

Yeah, its the ignition fuse. I'm assuming that the previous owner replaced the old fuse with that "new" one. I haven't had any ignition problems so I'm assuming that it is alright?

 

[hmusket]

I believe you are correct in your assumption about the wires. The one that looks black, probably red under the plastic, should go from the positive terminal to the starter solenoid. If you followed the red wire and it connected to the crankcase, it probably is a ground, unless its connected to the starter motor. Since I have an '81, and the wiring has been modified on mine by previous owners. I can't compare my wiring to yours. Perhaps someone with a '77 can come up with an answer about the wire your dad is pointing at. I'm guessing it may be a frame ground. Did you trace it?

 

[Joshwuh]

I followed the red wire to the crankcase and stopped there because I can't go further without taking the casing off. The black wire goes into a bundle of wires that go to the tail light and to the front in/around the headlight.

 

[hmusket]

The black wire (Dad's wire3) probably grounds the tail lights, headlights etc. If you put the positive from the car and charger on the red wire, the one that is actually a ground(most likely) and then connected the negative to the black wire your dad is pointing to, it would spark and maybe smoke just like if you touched the two jumper cables together. Since your bike was running, starting, etc. OK before this, the red wire that goes to the crankcase is probably the ground wire. You can look at the starter solenoid and see if there is a heavy wire that also goes to the crankcase area, but goes underneath the starter motor cover.

In all likelihood you're probably going to need a new battery and should also think about redoing your fusebox.

 

[Joshwuh]

So I should plug in my battery tomorrow and if it doesn't power anything I should buy a new one? Also, what does redoing my fusebox entail and why should I consider this? Thanks for the advice and sorry if those are dumb questions I am brand new to the MC world but eager to learn as much as possible.

 

[hmusket]

You could take your battery to a parts dealer and have them test it. As far as the suggestion to redo the fusebox, its more of a preventative measure. Looking at the picture you posted, the fuse holder with the missing fuse, (main fuse?), looks spread a bit on the right side and may not be holding the fuse tightly. Plus the fuse holder tabs can break at any time.

 

[Joshwuh]

Went out to hook up my newly charged battery (refilled the water last night as well) and turned the key to see if I could get lights... nothing. Reinstalled the gas tank thinking that I might as well try a bump start for shits and giggles. Once the tank was on I put the key in and the neutral and oil lights popped on, so I tried the electric start and she fired up better than she normally does for a cold start. Proceeded to ride around and she seems to be working fine now! I'm confused why the gas tank had to be on for the battery to work? Regardless thank you all for your help and advice it's really appreciated especially since this is my only vehicle at the moment. Now, to get her fully tuned up

 

[HoughMade]

You have a loose wire (or wires) somewhere. The tank has nothing to do with the electrical system. My guess is that the movement putting the tank on jostled something into making contact. My guess is also that if you don't locate the loose connection and remedy it, you will lose power at an inopportune time.

Like I said before, switch the ignition on and start wiggling wires until you find a place where the lights go on and off with the wiggling.

 

[Joshwuh]

Thank you for the observation! You are right the Main fuse holder is a bit loose as noted above and also once of the fuse box wires causes the lights to flicker. I will look into replacing those asap. Thank you for catching this! I am extremely grateful.

 

[drewpy]

One last question: At the top of the picture my dad is pointing to a wire, can anyone tell me where that goes and what it does.

it goes where your dad is pointing, its an earth lead and looks pretty grubby and I bet its not making a good ground either!