Low Voltage To Coil

[Guest]

One coil reads 9v the other reads 11v.
I was just wondering if the coil relay mod posted on Basskliffs site would work on a 83 GS 550?
If so would it be detrimental to any other system to ignore whatever is causing the voltage drop?
Also in thread linked below there is mention of a Dyna ignition that replaces the stock ignitor unit, would that be an option for my bike if it turns out the ignitor is bad?

http://www.thegsresources.com/_forum/showthread.php?231887-No-voltage-to-coil/page2&highlight=coil

[tkent02]

Clean up your wiring, it can't work right with corroded connections.

[60ratrod]

Sort out your electrical issues first. Having 9 on one coil and 11 on the other is telling me you have serious issues. In a good system, both coils should read the same, since the switched power splits off and goes to both coils, hence the same color. Figure out why and where you are dropping 2 more volts before thinking of other things.

[ColinClayton]

I fixed some frayed wires and cleaned all the connections then went to measure the voltage again. It seemed to fix it since they were both at around 11 volts after that, except I forgot to plug in the ignitor unit. When i did, the voltage drop returned. Does that point to a bad ignitor or should i still search for a mis-wiring?

[Steve]

When you plugged the ignitor in, current was able to flow through the coils.

Unless you have a REALLY good battery, voltage with current flowing will always be lower than open-circuit (no current flowing) voltage.

One more check to make before you call this project "done". While you are measuring 11 volts at the coils, what is your voltage at the battery? If it is also 11 volts, there is nothing wrong with the wiring, but you do need a new battery. The battery should not drop below 12 when the key is ON, before the engine is running.

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[60ratrod]

did it go back to one coil lower than the other, or are they now both reading the same voltage, just with the drop returning?

[ColinClayton]

Battery voltage is 11.97 when the bike is on, and about 11.50 at one coil while the other is around 9.
The positive coil connection with 9 volts switches from coil to coil intermittently when turn the bike on and off and I'm not switching any wires or turning the bike over. Is that normal??
Also there is a two way switch in place of a keyed ignition with a wire going to no where. Could this be the cause of the problem?
Here is a picture of the ignition switch wiring.
Ignition System Wiring.jpg

[Steve]

Voltage drop from 11.97 to 11.5 is not bad, certainly not worth doing a relay mod to "fix" it.

Lower voltage at differing coils could be caused by the ignitor. Normally, it will allow current flow through both coils, then, when the 'flag' on the crank tells the sensor to fire a plug, the ignitor will open the circuit to that coil, which causes the magnetic field to collapse, which is what makes the spark. If your case, one circuit or the other might know 'know' that it is supposed to be closed until the engine is running, so check the voltage with the engine running. THREE voltages: battery, left coil, right coil.

Not sure how that switch is wired to handle ignition chores. The wire colors shown are standard colors, but with no indication of how the switch is connecting them together, it really doesn't mean much. What activates the switch? What wires get connected to what other wires when the switch is activated?

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[ColinClayton]

I twisted the orange wire with the brown and grey and now the voltage to both the coils is about 10.40 when the electrical system is on and 11.50 when the engine is running. My idling problems have been solved along with a great many other things.

[tom203]

Now that it's running, test the charging system to ensure happy motoring...

http://www.thegsresources.com/_forum/showthread.php?164993-Charging-System-QUICK-TEST/page2&p=1272192#post1272192

[ColinClayton]

Great, it doesn't seem to be charging. Battery voltage is 12.5 when running but does not change at higher rpms.

[Steve]

I twisted the orange wire with the brown and grey and now the voltage to both the coils is about 10.40 when the electrical system is on and 11.50 when the engine is running. My idling problems have been solved along with a great many other things.

What's the red wire connected to?

In stock form, when the ignition switch is turned to ON, the red wire is connected to the orange wire. The brown wire is connected to the gray wire, but neither of them is directly connected to the orange/red pair.

What ELSE has been done to this poor bike that you have not bothered to let us know about?

Let's face it, that "different switch" thing is enough to mess up a LOT of stuff.

Is this a somewhat 'normal' bike or some radical 'custom' project?

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[ColinClayton]

The red wire is connected to one end of an on/off toggle switch and the rest are all twisted together and attached to the other end, so they're all wired together, I think. Now that sounds like a terrible idea from what you're saying. I only wired this in out of necessity because I lost the keys to the ignition.
I have been riding the bike with the wiring like this (minus the orange wire) for some time without too much of an issue until recently. Other than that, there have been no electrical modifications except for an LED headlight and stoplight. Also all the stock gauges aren't there and remain unplugged.