Just did WG wiring mod...is this normal?

If you have a tiny loss that is to be expected, in the small fractions of volts. Not approaching .5 volts.

Keep in mind all.... You must have at least +12Vdc on the battery to charge it, preferably as designed +14Vdc....

Even at +12Vdc, this would be a minimal trickle charge at most and you will eventually drain the battery and be stranded...

Push wifey/GF, push.... Faster woman... :laugh:

OMR

Also, the losses should only show up when there is current in the coil circuit. With a factory electronic ignition system, there is no current in the coil until the motor is actually turning (not just ignition on). With points, the coil has about a 50% chance of having current when the ignition is on but the motor is not turning. With the Dyna S, both coils will likely be "on" even when the engine is not turning.

If you see a voltage drop even when there is no coil current, that means the drop is due to the lighting sysem. When the coil gets current, the drop will be even larger.

Best to check the coil voltage versus battery voltage when the bike is actually idling (That's when most ignitions use the most current.)

loudhvx wrote:

Also, the losses should only show up when there is current in the coil circuit. With a factory electronic ignition system, there is no current in the coil until the motor is actually turning (not just ignition on). With points, the coil has about a 50% chance of having current when the ignition is on but the motor is not turning. With the Dyna S, both coils will likely be "on" even when the engine is not turning.

If you see a voltage drop even when there is no coil current, that means the drop is due to the lighting sysem. When the coil gets current, the drop will be even larger.

Best to check the coil voltage versus battery voltage when the bike is actually idling (That's when most ignitions use the most current.)

good info.....

bLodi wrote:

I feel I did everything right. I do also have the Dyna S ignition so I did to the extra step at the end of the mod if that has any relevance at all.
Thanks.

Here's the coil mod for reference...

Wow, thanks for all the replies.
I went back out yesterday and played with it more. I disconnected the jumper to the Dyna S as shown on the diagram (thanks for posting Bluemeanie) and that solved my kill switch issue. I must have had it jumped to the wrong wire coming from the Dyna S..there are several and the instructions said the red one. There was also a white and black wire...can anyone clarify? But the bike does run without the jumper...is it really needed?
Anyways, I tried just cleaning the old connections and while it seems to have helped slightly I was getting about 11.3 at the coils. With the new relay setup I am getting 12.4-12.5 So that seems significant enough for me to at least try it out.
For the record, I haven't had any issues that I was trying to resolve with this, but thought I would at least give it a shot to see if it made a difference. Still havn't had a chance to take it for a spin yet, hopefully this week, but I'll report back to say if I note any difference.

These early bikes had very simple weiring harnesses. I would still try to find the primary problem. The thing I would check is the Fuse holder and the connections to the fuses. They are a major culprit in low voltage. If you have a tooth ache, you have it fixed. You don't just take a pain killer to make the ache go away. :ohmy:

My 2 cents.Did the coil mod on my 650 last summer,didn't notice a change but had a warm fuzzy in the pit of my stomach.After switching pumper carbs for reg ones before starting bike this year, bike would not even sputter.Checked point gap and timing,( I know, I know...Dyna's on the list) all good still nothing. Pulled and replugged all coil mod connectors, hit the starter and bike started so fast I had to change my drawers. On the list of things to do today, pick up pile of wires on garage floor...post used relay on C-list.

I considered doing the coil modification, but checked the voltage at the coils and compared it to the voltage at the battery. With engine stopped, the voltage was about 11.5 at the coils and 11.7 at the battery. From this, I concluded that the difference would not be worth doing the mod, since the bike ran very well.

Now when I first got my motorcycle, after it had been sitting for perhaps 10 years, the battery would occasionally run down. Each time I would check voltage output it was within spec. The problem was intermittant. Finally cleaned and tightened every electrical connection in the entire system. Problem disappeared.

If you have 11.7V at the battery, the battery is going or already is bad. you should have about 12.5+/- with the key off.

Sorry if I did not explain very well. The readings were with the key in the ON position, otherwise there would be no coil voltage to measure. So, with the engine stopped, and the ignition switch ON, the headlight and parking lights are ON, and the voltage decreases from the 12.5 down to 11.7 due to the draw of the lights. Is this normal?

Understood.