Disconnect your DYNA S unit from the yellow and blue wires feeding the stock coils!!!!!
These things are killed by too many amps!!! The GM DIS coils will load the DYNA Unit to 15 amps with out a ballast resistor! They can only tolerate at most about 5 and really only want to see about 3.5. So be careful! And be warned. This can be very expensive if done wrong!
I have mounted the GM DIS coils
(from the wrecking yard off a four cylinder gm car for five bucks, compared to $157 from DYNA) in the frame by first removing the stock set and using the upper bracket hole to attach the new
coils bottom to bottom one on either side of the frame with one long screw through both using a nut behind each coil and on the screw to space the coils about a half inch apart. They fit nicely in the air flow above the radiator and behind the head tube. They get wired using 14 GA wire into the existing loom by first assembling four adapter wires. You will need to get four of the special male spade connectors that are extra long and designed to fully engage the coil primary contacts. Solder the male spade to a 7 inch length of wire and add a female spade suitable to the lug on the WELLS AL 795 Ballast. Make two of these.
Now make two more wires about 7 inches long, one end soldered to a male barrel compatible with the round twin socket that is connected to the black coil power lead. It is the stock connector where the positive side of the coils connected before removal. These two wires will supply power to one end of the ballast resistor. The other wires connect to the other end of each ballast with the male spade being inserted into one side of each coil primary.
That gets the positive side wired. The negitive side is simpler... Make two wires up about 10 inches long. One end of each wire gets a male barrel compatible with the socket of the yellow and the blue wire and the other gets one of the special male spades that fit the coil primary.
The ballast resistors (two--one for each coil) are bolted together through the mounting tabs with a large washer on the bolt and then place under the faux tank top beside the center hole that accepts the fuel guage when the tank top is down. I put mine in the left hole with one washer under the hole, on the bolt holding the ballasts together and another washer over the hole
on the bolt with a nut holding everything together sandwich fashion. That puts the resistors in the airflow under the faux tank top bracket and above the bike frame. Kinda tight but protected and out of the way.
I also had to cut about 2 inches off the air cleaner snorkel to clear the coils.
As I remember, the yellow coil wire feeds the coil that works the two front cylinders and the blue wire feeds the coil for the two rear cylinders.
!!!Do not hook up your DYNA S Unit yet!!!!
You need to condition the ballast resistors first. You do this by connecting a temporary jumper to the blue wire where the Dyna S connects normally, then ground it to the frame or negative battery post and turn on the ignition switch. The resistor will smoke and the resistive element will turn red.
These resistors allow about 12 amps to pass the first time they are
energized, but after this procedure, they will only pass initially about 5
amps and after warm up (a couple of seconds) 3.5 amps. Once this has
happened the ballast will now prevent the coils from drawing too much current. Do the same thing for the ballast connected to the blue wire and then you are ready for the next step.
I have not as yet taken this step. That is to hook up the Dyna S. I do not have the replacement yet.
Further research has shown that another option for protecting the Dyna Unit might be to use a transistor coil driver circuit. The Dyna S is a hall effect module... so a simple power transistor can be set up so that the pulses from the module can drive the base of the transistor and cause the collector and emitter to form a switch that can safely carry the current and
only present about 300milliamps to the Dyna S. It should run cooler and last alot longer. I have an email in to DYNAONLINE asking about compatability with transistor coil driver circuits, but have not had a reply. Probably because they market a fancy unit that does the same think at about $200. I built my own for alot less!
Short of the coil driver... I could simply reconnect the Dyna to it's original connection points (the yellow and blue wires). The system should now only draw at max 5 or 6 amps and after a couple of seconds of warm up 3.5 amps. That should work great. And give a way hot spark!
Late Breaking News.... Aug 5th
I got my modules back from the good people at DYNATEK. They are the makers of the Dyna S ignition system for the GL1000. I have had this unit for nearly three years! I killed it.... They replaced it under warrantee... no questions asked. They get my vote for customer service hands down. I was just 12 days from an expired warrantee period.
Good news is... everything worked!
Sorta...
The bike started and ran great until the coil driver circuit failed...
I connected the Dyna S directly to the coils and crossed my fingers...
Fired it up again and held my breath..
It ran! Good! Really Good!
Would not idle before this modification... now it sits at 850 and just lops along happily!
Throttle response is good and exhaust note has a crispness it did not have before this project. (very subjective analysis...)
I still need to test the current draw on the Dyna S unit. But initial tests show that it is not getting hot. So far so good!
The ballast resistors are kinda warm to touch. Not hot... just warm.
I still have to ride the bike to satisfy myself it will work out ok... we shall see...
Aug 30...
Back at it again... I got things all back together and road the bike about 100 miles.
It was great! Smoother and better behaved than I have ever felt it. Seemed to be more responsive and powerful too.
All in all, I am very satisfied with this conversion. I spent about 30 dollars and a few hrs time to get a bike that is a better ride than when I started.
April 2002
Bike is hard starting after it is warmed up... I think there is too much voltage drop when the starter is engaged.
Found it necessary to add a ballast bypass to the circuit. It consists of a single wire connected to the electrical terminal on the starter, running thru each of two diodes via a "Y" and then directly to the positive side of the coils along with the wires from the ballast resistors.
What this does is to provide full voltage and current to the coils only while the starter button is depressed. This will give maximum spark for starting and then limit current thru the resistors when the button is released.
Comment...
"I think you would be wasting your time building a coil driver... there is already one in the Dyna S.."
Reply..
That's true... But it can only safely sink about 5 amps long term (that is a guess)... The GM DIS coil can draw as much as 15 amps... With the ballast installed that is reduced to approx 3.5.
I made a coil driver circuit that will sink 15 amps, has a heatsink on it and does the heavy lifting for the Dyna S unit... With the ballast installed, this driver will provide another layer of protection for the expensive parts, allowing them to run cooler.
Construction Details for the Coil Driver
I purchased all parts for this project from a local electronic surplus store.
Parts List:
T1 - 2 TIP 2355 PNP Power Transistors
R! - 2 39 Ohm 5 watt Resistors
1 Suitable heatsink.
Dielectric Grease
HeatShrink Tubing
The transistors are rated at 15 amp in switch mode. Almost any PNP transistor will work. Look for one with a high power rating.. as in it will carry a bunch of amps... Just make sure you can heatsink it properly.
Connect the emitter to the negative side of the coil, the base gets connected to the Dyna S unit signal wire though the 39 ohm resistor and the collector gets grounded through the heat sink.
When the base goes low (ie. grounded) it switches the transistor to ground and completes the circuit to fire the coil. The drawing above, though crude, details the parts arrangement.
Aug 5th update..
I built it... it worked for a few minutes... Then it died. It looks like the junction broke down. I am thinking I should use a NTE 2329 Transistor. I may try again... but the bike runs without it. See below for the details.
Here's an interesting link describing DIS troubleshooting and theory.....
