Tough Electrical Problem on my 1987 VFR700

I haven't been on a VFR forum in 10 + years. I do most everything myself. Thanks in advance. The bike was working great. The other day, went to start it... nothing. No lights, no indications, etc. Putting the key into the ON position brings the battery voltage from 12v down to zero... but it does not seem to be a dead short. The battery does not get hot or lose a lot of voltage. Pulled all the fuses. Now the battery voltage stays at 12v. Putting in the Ignition Switch Fuse is the culprit.... brings the battery voltage down to zero. I have the mechanics documentation and the schematics. Looking at the schematics, I've tried troubleshooting but nothing found yet. Where should I go next? Start disconnecting all the connectors? What could cause this? Bad Spark Unit? thanks all.

 

I would start with the assumption that the battery is kaput. In my experience they can have enough resting voltage to fool a battery charger into thinking it is full, but there is next to no ability to flow any meaningful current. Try jump starting off another battery, but take the old battery out of the circuit first. DAMHIK.

 

I second the motion by Terry. If it were me, I would start by pulling the battery out, charge it overnight, and have it load tested. If the batt is the problem, it is an easy fix. Do you know how old the battery is?

 

You guys were totally-dead-nuts-on-target. The battery was showing 12V but isn't putting out any amps. I feel stupid... but I feel good that you guys saved me lots of hours pulling connectors and not making progress. New battery is due on Monday. THANKS SO MUCH.

 

Great news.

I was all set to call in an auto electrician for my daughter's car, which seemed like it had a full battery (overnighted on a charger), but would only rattle the solenoid when I turned the key. I tried jumper cables from another vehicle with the same result (and the cables got warm), so I was all set to assume that I had a bad solenoid. When I discussed this with a mechanically-savvy colleague, he diagnosed a failed battery with an internal short, and sure enough a new battery solved the fault. The old battery was shorting internally which was why the jumper cables got warm but still wouldn't turn the engine over. Now a failed batery is my default suggestion for most electrical woes, especially of the "worked yesterday, won't start today" variety. Seems like they just die, maybe during that last ride with vibration and bumps, but we don't notice until the battery is called into action for the next start.

 

Good to hear Somnabulist!

Your next post should be on the introductions forum. When you do post there, do us all a favor and upload a photo or two of your VFR.

 

Down-under Terry is a fountain of info, good, smart info !!