• Required reading for all forum users!!!

    Welcome!
    Register to access the full functionality of the GSResources forum. Until you register and activate your account you will not have full forum access, nor will you be able to post or reply to messages.

    A note to new registrants...
    All new forum registrations must be activated via email before you have full access to the forum.

    A Special Note about Email accounts!
    DO NOT SIGN UP USING hotmail, outlook, gmx, sbcglobal, att, bellsouth or email.com. They delete our forum signup emails.

    A note to old forum members...
    I receive numerous requests from people who can no longer log in because their accounts were deleted. As mentioned in the forum FAQ, user accounts are deleted if you haven't logged in for the past 6 months. If you can't log in, then create a new forum account. If you don't get an error message, then check your email account for an activation message. If you get a message stating that the email address is already in use, then your account still exists so follow the instructions in the forum FAQ for resetting your password.

    Have you forgotten your password or have a new email address? Then read the forum FAQ for details on how to reset it.

    Any email requests for "can't log in anymore" problems or "lost my password" problems will be deleted. Read the forum FAQ and follow the instructions there - that's what we have one for...

  • Returning Visitors

    If you are a returning visitor who never received your confirmation email, then odds are your email provider is blockinig emails from our server. The only thing that can be done to get around this is you will have to try creating another forum account using an email address from another domain.

    If you are a returning visitor to the forum and can't log in using your old forum name and password but used to be able to then chances are your account is deleted. Purges of the databases are done regularly. You will have to create a new forum account and you should be all set.

voltage to coil

  • Thread starter Thread starter scrapper
  • Start date Start date
S

scrapper

Guest
I have been trying to sort out a problem with only 1 coil firing. I have tried 3 different coils and it still wont fire. I checked the voltage on the good firing coil and only 1 wire had voltage going to it. The bad side shows the same voltage on both wires. I was wondering if anyone could tell me what may be bad? I'm thinking it would have to be a short in the wiring or the ignitor may be bad.I had to clean the signal generator because one side was oxidized, It would not read from just the metal on the outside to the metal on the inside. I'm not sure what that piece was, maybe the pickup? I cleaned it up really nice. It still has same problem. Thanks for any help.
 
scrapper said:
I have been trying to sort out a problem with only 1 coil firing. I have tried 3 different coils and it still wont fire. I checked the voltage on the good firing coil and only 1 wire had voltage going to it. The bad side shows the same voltage on both wires. I was wondering if anyone could tell me what may be bad? I'm thinking it would have to be a short in the wiring or the ignitor may be bad.I had to clean the signal generator because one side was oxidized, It would not read from just the metal on the outside to the metal on the inside. I'm not sure what that piece was, maybe the pickup? I cleaned it up really nice. It still has same problem. Thanks for any help.
Click to expand...

You need to understand how a coil works and how it works with the ignitor/points.

The O/W wires are switched +12V and come on with IGN switch and kill switch. That should stay on. These are the Coil(+) wires.
The B/Y and W wires are the Coil(-) wires. They will go up and down in voltage as controlled by the ignitor/points.

When the Coil(-) goes from near ground to +12V you should get a spark.

The 1-4 and 2-3 coils should spark alternately.
 
Okay, I tested with key on and that is when I found that 3 of the wires were reading the same. I would think that 2 wires would not be reading anything or would be really low? I am really bad when it comes to electrical stuff. I have searched a couple of times.

EDIT-
I just re read your post and was wondering if you mean 3 wires should be hot because the pick up is aligned with one of them? I was also wondering if I cleaned the pick up correctly? I used a little sand paper and some wd-40. The metal part that goes through the plastic was oxidized so bad it would not read the ohms. It did after I cleaned it though. I did not check but did start to wonder if you need to re-adjust the space between it and the shaft, or if it was even possible to. It looked like it wasn't adjustable. One coil is not putting out spark. That is why I thought it was the ignitor or maybe the signal generator. I thought it may have had a problem with the stator but it showed the same reading on all 3 wires and they were not going to ground. Like I said I am really bad when it comes to electrical stuff.I can wire a house but it is not the same with a bike or a truck. You may have to get out the crayon and a piece of paper and go real slow???
 
Last edited:
You need to read and follow this link
http://members.dslextreme.com/users/storagecliff/images/electrical_odd-n-ends.html#A17

this breaks ignition down into the individual items that must work. You want an ignition coil that measures about 4 ohms primary. Across the blue and green wires from signal generator ,you want about 300 ohms. Don't bother to measure voltages at signal coils.Try switching the B/Y and W wires at ignition coils and see if the previously non working coil now sparks. But first check primary and secondary resistance of ignition coils as in the above link- they should be about the same.
 
no voltage at the lead for the ignitor,voltage on the fuse block is a lot lower about 8v than across the battery. I'm guessing I should pull the ignitor out and check the wires?Would that make it only run on 2 cylinders?
 
scrapper said:
no voltage at the lead for the ignitor,voltage on the fuse block is a lot lower about 8v than across the battery. I'm guessing I should pull the ignitor out and check the wires?Would that make it only run on 2 cylinders?
Click to expand...
Fix it ...........
 
Sounds like the signal generator or ignitor. And wd-40 is bad for electrical components. Have you checked for the ohms at the blue/green wires coming from the signal generator? You must check them at the plug that sits behind the left side cover. If that's good, you need to do the ignitor test. But without the engine running, the b/w and w wires on either coil should have little to no voltage going to them, just the o/w wire on the coils. I had the same problem with my 81 gs650g a couple weeks ago, and it turned out to be the ignitor, but without testing the individual components in the system you will just end up chasing your tail like I did before I really looked at every component rather than just guessing and throwing parts unnecessarily at it (coils were what I threw at the it and bought a signal gen I never ended up needing) and hoping to magically find the answer here without having to do any trouble shooting. I wasted more time than necessary doing that
 
my plug for the signal generator was under my seat. I checked it for ohms. seemed okay? I will double check everything before buying any parts. It does not have any juice on the plug for the ignitor.I will try to check it out tonight. I am going to get a better voltage meter first, mine is having issues. Thanks for the quick responses.
 
Okay I do not get voltage on the igniter plug with the key on kill switch to the off. I tried to read it with the kill switch to the on,and it read 12 volts. What is wrong with it? I am really bad at electrical anything.The info I used for the tests didn't give any idea if it failed.Thanks for any ideas.

edit: There was not a voltage drop at the fuse box.
 
Last edited:
Clean the 4 wire plug that connects to ignitor- this feeds 12 volts to ignitor and also connects ignitor to ignition coils so they can fire when commanded.
 
Okay, but I hit them with sandpaper and then some light bulb grease. I am thinking I will have to look farther in the wiring ? I have hit all the connectors right there. Where is the next connection farther down the harness? Just to make sure it is the plug that is attached to the harness? I am going to cut all those old bullet connectors out, cleaning may not work.The spade connectors in the 4 wire plug kind of move a little like they are loose in the plug. I am thinking maybe that is a problem at the plug? I can just cut the plug out and replace with spade connectors if it is bad.
 
You'll be better off in the long run to just clean all of the connectors and inspect the wiring throughout the bike. You might find something other than just a connector in the same path as the coil is causing your problems
 
I have to tell you I get a little nervous taking electrical stuff apart. House wiring isnt to bad but auto and bike stuff kicks my butt. I will start unwrapping the wiring harness some to see what is going on. I am confused about why there is power with the kill switch turned on but not turned off. Why does it need to do that?
 
If you take pictures of the areas you have questions about and then post those questions, people will help you through it. Trust me, I don't know electrical very well either but doing that helped clean up a lot of my own messes.

When you say the kill switch is on do you mean when it's in the run position?
 
on to kill bike off to run bike. I can take some pictures will be out there today.


edit- I just re read link and think it meant key switch on and kill switch to run. I was thinking kill switch on meant so it killed the bike. That is why I was confused. I can move on to the next test. I already pulled the plugs out the 2 that were not sparking, they are wet and darker brown. I am guessing that may be a problem?
 
Last edited:
Better to think "off/run" then "kill". In "run" position, 12 volt positive is fed thru switch,feeds both ignition coils (the orange/white wires), and o/w wire then continues on and connects to that ignitor plug to feed the ignitor 12 volt positive. A black/yellow wire and a white wire runs thru that same plug and connects to their respective ignition coil.

EDIT: you can check for continuity of the b/y and white wires thru harness (from that plug to each ignition coil) with your meter's ohm setting. With ignition "OFF" (yes, OFF ) stick one meter probe in plug and other probe on corresponding connector at ignition coil- you should see zero ohms -meaning good connection!
 
Last edited:
I just did that .2 to .3 and one was 1.3 and it was on the side that works. I did the igniter test with a AA battery and the only way it sparked was to reverse the pos and neg wires on the battery then only the side worked that was working before. Anything else to check out? Should the coils have 12 volts to all 4 wires with the ignition on? I was thinking that 1 wire on each coil is 12 volts but the other wire was less?
 
Sure sounds like half of ignitor is not working. I'm skeptical cuz I've tested 5 of these ignitors (running on my bike) and all were good. But your testing says ignitor.Anyone in your area with 650 shafty? It's easy to swap in another unit and test it as there's no need to actually mount it- just plug in and test.
 
I don't think so. Can I put a dyna s on this? I did see the gm modules wired together, but again it wasn't for a 650. I looked up the part number and it said 81-83 G,GL,M were only ones. I have looked on ebay but not sure if its just the plugins that are different but several have different numbers but look the same. How can you tell what will work and what wont. I have read so much info my eyes are crossed.
 
I'm still going to check out the rest of the wiring just to make sure there are no problems.I am thinking you can't take these igniters apart?Or is it possible?
 
You must log in or register to reply here.
Back
Top