Voltmeter spazzing out

Hey guys,

My Seca 550 seems very happy now, took a nice ride up to Lake Ontario the other night, so now I suppose it's time to sort out the little things...


So toward the end of last season (especially when it started getting cold), the gauge cluster would periodically make this horrible buzzing/whining noise. I was finally able to narrow it down to the voltmeter. I notice at times the needle will fling all over the gauge, so violently at times that I fear that it is going to break. I read Fitz's breakdown of the gauge cluster in hopes that there might just be a bushing in there that dried up and fell out and it would be a simple fix, but it doesn't appear that there's much in that gauge that could go bad. The whine will occur pretty much at random, usually when the bike is cold and I'm leaving my neighborhood. It will stop once I get under 10 mph coming to a stop. Sometimes the gauge will freak out and fling around, sometimes it reads normal but still make the noise, so I'm not quite sure if it's a mechanical issue with the gauge or an electrical issue. I have noticed the gauge flinging around on the road, maybe under hard acceleration (obviously not watching the gauges too much while at speed), and it will usually return back to steady after I let off the throttle. I just read something about these things having a tendency to overcharge due to tarnished connections, could this be a symptom of that? I haven't really given the electrical system a good inspection, I kind of take it for granted because my knowledge of electronics is pretty lacking. I will tear into anything mechanical, but wires scare me, and since the bike runs fine, I don't really want to make a headache for myself if I don't have to. That buzzing is so obnoxious though... Wish I could get a video, but that wouldn't be too safe with my phone in one hand. Maybe I'll steal my roommate's Go Pro. Any electrical guys want to take a stab?

Thanks!

 

i think you may have two problems. the mechanical speedo cable and i believe the 550 has a mechanical tach are probably the noise you hear. i've never heard a
volt meter make noise. look for the three wire plug that comes from the alternator, that's where the over voltage plug melt happens.
inspect the wires where they go around the steering neck. you really should clean and grease all the electric plugs

 

That could very well be the case, the noise and the spazzing both cut off at low speed. And at high speed, I'm honestly not sure if it comes back with all of the road noise. I'll have to go through that whole system. Is it possible to grease the speedo/tach cables? They were working their way out last season, so I used some blue locktite to keep them in place.

As far as over voltage plug melt... I just had the alternator out and it looked fine, same with where it plugs in. Not sure what to look for specifically. Nothing looks burnt though, and the bike charges fine.

 

you can pull the inner cable out of the sheath and wipe it off, then smear it with grease and put it back in.
the volt meter probably has a bad connection somewhere, when it loses contact it swings to zero but then when it makes contact it over shoots and you see wild swinging. seems like it has something to do with the vibration. try turning the bike on and wiggle some wires and connectors

 

So after spending about 5 minutes riding around an empty campus parking lot with my hand wedged in between my faring and my gauges, I confirmed that the vibration is indeed coming from the speedo cable. Since I was able to watch it without fear of hitting anything, I'm almost certain that the vibration is what is causing the voltmeter to go nuts. I'll pull it apart, grease up the cable, and see what happens. Thanks for pointing me in the right direction!

 

I had a jumpy volt meter it ended up being a broken leed on a resister in the gauge. I was able to repair it with some skillful soldiering.

 

The whine is indeed either the cable, tach or speedo. Often this is an issue with the xj700 cluster. We call it the 'death scream'. mY 700 speedo only does this when the temp is below 55. It's funny on mine, it only does it when temp is below 55 degrees, and only if I go over 55mph at those temps. A once it gets about 55 degrees, it doesn't do the d earth scream, either.

When it starts screaming, it will always stop when ai get down to about 23mph. At that speed, the need gives a sight bounce when the noise stops, and I can speed back up to just under 55mph

 

I've also got the bouncing voltmeter needle. Good to know it's not that big of a problem.

 

My XJ550 mechanical Tach/Speedo made a mechanical buzzing sound, even after cleaning and lubing the cable and guages. I put black foam rubber between the meter body and the plastic snap in cover around the key. That put pressure on the guage housing and solved the problem. The Maxim guage layout is different, but you might try the same.

The black foam actually gives my dash a more "finished look."