I just got my '04 500F out of storage for the riding season. I had taken the battery out and kept it in a climate controlled place but not on a charger. I gave the bike a good once-over and then put the battery back in it and tried to start it up. I got nothing....no lights, no horn, no start. I gave the bike a jump to get it going and everything seemed fine. I took the bike out for a ride to get some juice back into the battery and noticed the Tach wasn't registering anything. The Speed-o worked but the tach registered 0... sometimes the needle would jump up to 5K and then drop to back to zero. Could a low charge on the battery cause an erratic tach reading? I've got the battery on a charger now to see if a full charge will make a difference. Thanks in advance for any help....
The tach on the late models (04+) is electric.
I would think that the signal would be present if the bike was running.
Let us know after the battery is topped off (Don't forget to check the fluid level).
I wouldn't think so.
When the bike is running everything electric runs of the alternator first and then any juice left over is used to charge the battery. Hence why on short rides you can stil get flat battery because its not getting enough juice over the ride to charge up and make up for what it cost to start it.
I believe that is the case anyway. Alternator runs everything chargers the battery second so the tach should work regardless of the battery.
I would check the tach cable for loose connections and if its not that then the magnets on the alternator which run the tach might be unaligned or something to do with that. Im not familiar with the GS tach or alterntor.
Corroded connection. That is the first thing I look for when anything electrical goes wrong with the GS.
I think it could be the low battery. On my mustang with an electric tach, when my alternator went out, the tach would twitch and jump all over then it did nothing. Then my car died. :cry:
Anyways, get the battery all charged up and then try it again. If it works :thumb: problem solved if it dosn't, then start looking at connections.
Either way I would think that after a 20 minute ride, the battery would be plenty charged up :dunno_white:
Quote from: ducati_nolan on March 14, 2007, 11:10:45 AM
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Either way I would think that after a 20 minute ride, the battery would be plenty charged up :dunno_white:
Charging is really only effective over 5000 rpm.
I had the same problem and a new batt fixed it. Once enough juice builds up to break the threshold, the tach needle gets jumpy.
SitRep on the Wonky Tach.... I put the battery on a charger yesterday while I was at work. I checked the battery with a voltmeter before I put it in the bike and it was reading just shy of 12 volts and around 10 amps. Put it in the bike and she fired right up and the tach worked just the way it was designed to. All of the comments about the alternator are definitely correct. I checked the current with the battery hooked up and the bike running at idle and it was just over the battery's native voltage and amperage and didn't jump to where the battery would be getting a substantial charge until around 4500 RPM. Now that I've gotten the bike back up and running the weather has turned nasty from 70 degrees and sunny to cold and rainy so i'm gonna have to wait a few more days to get back out on the road...typical. Thanks for all of the help everyone...
Yes, a low battery would make the tach USELESS.
I have proven this by running the gs and taking the battery out WHILE the engine was running.
*The headlight flickered a lot
*Tach didn't work
...but surprisingly, the engine was still puttering (weakly).