Who put those extra wires in there...?

[coy55boy]

I'm trying to figure out what everything is before replacing my fuse box (I ordered the kit SkyDoc sells in classifieds). I've got a couple of items that don't make sense to me and maybe you can help.

 

First off, there's a device that's attached to both terminals. I suspect it might be a noise reducer or some such, but it would be nice if someone knows for sure.

 

The other is a blue wire that terminates on the Batt. + and then is connected to a White/Red wire in the main harness behind (or in front of) the battery. I disconnected it from the battery and everything 'seems' to work OK. Again, I'd appreciate any input here...

 

http://i112.photobucket.com/albums/n163/coy55boy/83%20Venture%20Royale/fusepanel.jpg

[BOO]

I'm trying to figure out what everything is before replacing my fuse box (I ordered the kit SkyDoc sells in classifieds). I've got a couple of items that don't make sense to me and maybe you can help.

 

First off, there's a device that's attached to both terminals. I suspect it might be a noise reducer or some such, but it would be nice if someone knows for sure.

 

The other is a blue wire that terminates on the Batt. + and then is connected to a White/Red wire in the main harness behind (or in front of) the battery. I disconnected it from the battery and everything 'seems' to work OK. Again, I'd appreciate any input here...

 

 

The gadget hooked to both terminals looks to be a Capacitor in shrink wrap. Would probably be for some kind of noise control.

 

I have no idea about the blue wire but it probably hooked up an accessory that the PO might have installed.

 

Been a while since I've had a first gen so I don't remember but I know that Cap was not original equipment.

 

BOO

[dingy]

The white red wire may be part of the battery level sensor.

 

Does your battery have a hole in the same area as the fill plugs with a sensor plugged into it? If not it may be a bypass put in at some point. Some replacement batteries did not come with the sensor hole, so the wiring mod was required to discountine the warning on the CMU.

 

But, if it is a bypass, when you disconnect it there should be a warning icon come on. also there should be a flashing red light for about 60 sec.

 

The other item between the pos & neg posts may be a noise reducing capacitor as you suggested. It is a fairly small size to have much effect though. With capacitors, bigger is better when it comes to noise reduction. The capacitor that Yamaha started installing on the MKII Ventures is about an 1" dia and about 2 1/2" long for comparison

 

Gary

[Flyinfool]

That "extra device" looks like it might be a capacitor, If it is a capacitor (which could be used as a filter) It is hooked up in a way that it is doing nothing at all.

 

As far as the blue and white/red wire...

[coy55boy]

The white red wire may be part of the battery level sensor. Gary

 

Gary gets the prize! I had the instrument panel covered with a rag cuz the handlebars are draped over it. I went and checked and sure enough, I get a battery warning. Thanks Gary!

 

The other device...I'm still not sure about. I suppose it could be a capacitor, but it's got a wire coming out of either end. Every capacitor I've ever seen has both wires coming out of the same end. Of course most capacitors I've seen were made to fit on a PCB board. But, this looks suspiciously like a resistor. Hmmm, just don't make no sense....

[dingy]

That "extra device" looks like it might be a capacitor, If it is a capacitor (which could be used as a filter) It is hooked up in a way that it is doing nothing at all.

 

As far as the blue and white/red wire...

 

The purpose of the capacitor across the positive and negative battery terminals is to allow the "Plates" of the capacitor to smooth out spikes in the power system. Think of the capacitor as a larger buffer. When a short term spikes in the power system occur, this buffer smooths out the spikes in the noise. If the spike is of sufficient duration or power, then the capacitor is overwhelmed.

 

If you were to look at the DC voltage on an oscilloscope, there would be a constant line showing the 12vdc. Superimposed on this line, there are very small spikes of voltage that cause static in electronics gear. Sources of this static include emissions from the ignition coils, relays opening and closing, speedometer sensors, tachs, metal rubbing, etc.

 

This is where the size of the "plates" comes into play. The larger the surface area of the "plates" the more the capacitor is able to absorb, or smooth out, the noise spikes.

 

The "plates" of the capacitor are two very thin sheets of foil, separated by an insulator, one piece connected to each lead of the capacitor.

 

The capacitor acts like a block to DC voltage, in other words, DC voltage will not pass through the capacitor. What will happen when the circuit is powered up is the capacitor will acquire a charge, or potential difference, equal to the system voltage. When the circuit is powered down, the capacitor will then discharge back into the circuit. This discharge rate is determined by the resistance in the circuit that the capacitor is connected across and the size of the plates. On my 83, when I put in the 88 wiring harness and two capacitors that are included in the MKII's, my after market radio will continue to play for about 45 seconds after the key is turned off. This is due to the capacitors storing a sufficient charge to power the radio for that duration.

 

The use of a capacitor as described above, causes zero current drain on the system, after the initial charge, which is almost instantaneous.

 

Gary

[MikeWa]

It appears one terminal on your fuse box is positive and one is negative. If so the capacitor (filter) is correctly wired in. It is a capacitor or possibly a limiter diode but not a resistor. Filter capacitors reduce noise or static. They can be installed anywhere in the power line and can have wires on either end or both ends depending on design. They are connected between positive and ground. Limiter diodes limit voltage spikes due to reverse EMF. They protect computer circuits and are usually installed near the device they are trying to limit. ie blower motor or ac compressor and occasionally a power relay. Not likely on a motorcycle.

Mike