sudden loss of power

[gltriker]

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[Sidecar Bob]

I think sidecar Bob has a good point. I thought of using the black wire with a white stripe, but after looking at the wiring diagram it uses the same same fuse as the turn signals, etc. This is the 15 amp fuse.

I don't see the black/white connecting to any fuse (other than the main fuse) on the drawings for any GL1000.
In every case power comes from the black (switched power) to the resistor, from the resistor via the black/brown wire to the kill switch and from the kill switch to the coils via the black/white.
When the Start button is pressed power from the black wire is connected to the yellow/red, which runs to the coil of the solenoid and the diode that bypasses the resistor during starting.
When the Start button is not pressed power from the black wire to the black/red wire that runs to the headlight fuse is interrupted turning the headlight off.

The only possible connection between those circuits and the 15A (turn signal & horn) fuse is that the fuse also gets power from the black wire, but if you follow the circuits all the way through everything else on the bike ultimately gets power from the black wire too.

At any rate, the black/white wire is not a good place to connect the Dyna S to on a GL1000 because power to it has to pass through the resistor (except when the Start button is pressed).
I would connect it to the black wire at the resistor, with or without a fuse.

As for whether or not it needs a fuse, neither the points ignition in the GL1000 or the TI system in the 1100 are protected by anything other than the main fuse. I don't see a problem adding one if it would give you peace of mind but read this before deciding:
Mine is a very rare case of an 1100 with Dyna S. It had a 1000 engine with points for many years, then converted to Dyna S. When I changed to an 1100 engine a few years later I kept the Dyna so that I didn't have to change to 1100 carbs.
1982 & 83 1100s have the resistor but it isn't bypassed during starting so the black wire connects directly to the kill switch and the black/white runs from the kill switch to the resistor with the other end of the resistor connected to the coils.
When I changed to the Dyna I looked at the instructions and thought "why would I run a wire the turn signal to get power when there is already a wire that is live except when the kill switch is off?" and connected to the black/white at the resistor. (A few years later I replaced the '83 coils with ones from a GL1500 and eliminated the resistor but the Dyna still gets power from the black/white with no fuse).
It has been connected that way for almost 10 years with no problems that a fuse could have prevented (one of the Dyna's modules failed but the only effect was no spark on the rear cylinders).

If I was doing it again I would at least think about adding an inline fuse holder with an appropriate fuse (I'd want to measure the current it draws when the engine is running before deciding on a fuse value but based on how much the voltage changes when I turn the kill switch on or off I'd expect to need at least a 10A) but on the other hand I'm not going to worry about adding one after all these years.

[sickradsean]

Used the advanced search to find the answer was already in this thread . Thanks Bob! I'll try the black/white coil ignition wire and see if a more secure splice in helps.

[Sidecar Bob]

Read it again. I just edited it this paragraph to clarify:

At any rate, the black/white wire is not a good place to connect the Dyna S to on a GL1000 because power to it has to pass through the resistor (except when the Start button is pressed).
I would connect it to the black wire at the resistor, with or without a fuse

The black/white is only a good place to connect the Dyna's power wire on an 1100 (I wonder if I'm the only one who has done that?)

[cfairweather]

I looked at the diagram again and I agree that the the black wire and the black/white wire are fused by the only the main fuse so for this reason I would not use either of these, even if the ballast resistor has been removed. If you don't fuse the Dyna, you have a safety issue: For example, In the unlikely event your Dyna fails in a way that blows the main fuse, you will not have lights, brake lights or anything else. I think safety was the original reason that Bob suggested not using the turn signal wire for power. It is easy to add an inline fuse and it could save your life if you are flying down the highway at night.

[Sidecar Bob]

It would be a simple matter to add an inline fuse holder between the black wire at the resistor and the Dyna's power wire.

[redglbx]

I’m considering adding a relay to provide full battery voltage to my dyna, maybe use the black/white wire to switch the relay on/off. Any thoughts on doing this ?

[cfairweather]

You won't gain any more voltage with a relay. Just add an inline fuse to the red Dyna wire and connect it to the black wire. The black wire is only live when the ignition switch is on and connects to the main fuse.

[Sidecar Bob]

It depends on where you connect the relay. If you connect the relay directly to the battery you might get a bit more.

Using a relay triggered by the black/white could actually be a good idea, if only because you could turn off the Dyna with the kill switch (assuming the voltage after the resistor will power the relay.)

[Shadowjack]

The only way you can get more voltage by adding a relay is because it bypasses all the connectors in the harness, which have 40 years of corrosion built up in each one. Each dirty connection drops the voltage just a little tiny bit, but it can add up. In electronics terms, the whole path becomes a voltage divider.

[Sidecar Bob]

Not only the connectors but the connections inside the harness, not to mention the wires to & from the relay bring shorter than the wires from the battery to the keyswitch and from there to where you would connect it (all wire has some resistance) .

If the harness is in good shape I would expect the gain from using a relay to be negligible, but being able to turn off the Dyna with the kill switch can be handy.

[sickradsean]

OK so then black wire at the resistor with an inline 15A fuse seems to be the consensus? I don't have a ballast resistor anymore since I installed the Dyna coils, so just splice off the black wire that is plugged into the black/brown wire at the coils?

[Sidecar Bob]

Yep. 15A would be at least high enough but I'd want to measure the current with the engine running at about the RPM it would on the highway and pick the next common value above that.

[redglbx]

I would add a couple of thoughts, check that your gas cap is venting properly, next time it acts up loosen the gas cap and see if that improves the running. The gas caps in these bikes seems to have problems with the vents due to rust/spider webs/sticking spring loaded flap.

Also most people (myself included) think the slide sticking is caused by the large diameter of the vacuum slide so there’s all kinds of ideas & procedures for cleaning those BUT the real issue is more the slide pins so you need to really have those clean. Q-tips really help get the cap side pin bearing clean.

[sickradsean]

I changed the wiring of the Dyna S to get power at the black+black/brown wires just outside the coils (with an inline fuse). Still drops all power after warm up. I looked into testing the Dyna S module

https://www.mpsracing.com/instructions/ ... esting.pdf

and it says to disconnect the wires from the coils then OHM test between the backing plate and the wires. It should read open and any other reading means a damaged unit. So when I did this my reading never changed and stayed at (1) on the multimeter. So time for a new ignition module?
(I'm just double checking that I read and followed directions correctly because who knows where my brain is these days)