Testing ignition coil 2000 R 1200 C

[wbw6cos]

Good morning,,

Wanting to know if I am checking the ignition coil properly with a multimeter.   Some online research was vague enough for me to question my testing method.

 

I tested ohms and continuity between #1 & #2 in my picture, getting .5 ohms in the 200 ohm scale.   That should be primary, right?   Then to test secondary, I put a meter lead on 1 or 2 and the other lead on 3 or 4 and all combinations and get no reading.  I switched the meter to higher ohms scale.  Also, no continuity beep in said checking (above.)   My H/T leads read between 55 and 60 k ohms.   I have an older used set of leads that test similarly.   

Am I testing the coil properly for secondary?

 

I had a no-start electrical pop with smoke billowing out of oil cooler vents, which is why I have the coil out for testing.   

 

Coincidentally,  5 year old PC680 battery was hot, which I disconnected.    It tested 11.39 v the next day and the battery was swollen and hard to pull out of the battery tray without prybar action.   New battery is on order.  A a few days prior, I pulled the bike off the CTEK 4.3 tender in snowflake mode.  All green lights were lit and I keep the bike on the maintainer during the time I am no riding it to work.  

 

Curious if the two or related or not.  

 

I suspect my ignition coil is bad.

 

Thanks,

 

 

[dirtrider]

6 hours ago, wbw6cos said:

Good morning,,

Wanting to know if I am checking the ignition coil properly with a multimeter.   Some online research was vague enough for me to question my testing method.

 

I tested ohms and continuity between #1 & #2 in my picture, getting .5 ohms in the 200 ohm scale.   That should be primary, right?   Then to test secondary, I put a meter lead on 1 or 2 and the other lead on 3 or 4 and all combinations and get no reading.  I switched the meter to higher ohms scale.  Also, no continuity beep in said checking (above.)   My H/T leads read between 55 and 60 k ohms.   I have an older used set of leads that test similarly.   

Am I testing the coil properly for secondary?

 

I had a no-start electrical pop with smoke billowing out of oil cooler vents, which is why I have the coil out for testing.   

 

Coincidentally,  5 year old PC680 battery was hot, which I disconnected.    It tested 11.39 v the next day and the battery was swollen and hard to pull out of the battery tray without prybar action.   New battery is on order.  A a few days prior, I pulled the bike off the CTEK 4.3 tender in snowflake mode.  All green lights were lit and I keep the bike on the maintainer during the time I am no riding it to work.  

 

Curious if the two or related or not.  

 

I suspect my ignition coil is bad.

Morning William

 

You have it a little mixed up__

 

Between (1) & (2) is the primary & should measure about .5 ohms at room temperature. 

 

Between (3) & (4) is the secondary & should measure about 13,000  (give or take) ohms at room temperature. 

 

Later coils will usually measure 7k - 7.5k between (3) & (4) at room temperature & measure about 1 ohm between (1) & (2) at room temperature . 

 

You should NOT show any continuity between the  primary  (1) or (2) to the secondary (3) or (4) as the primary & secondary windings are isolated from each other. 

 

 

[wbw6cos]

Good morning dirtrider,

 

Thanks for the reassurance.    I got continuity beep between my 1 & 2, but also resistance.   Not sure what that was all about.   

 

Test probes between my 3 & 4 measured nothing.  Between 1 & 3, between 1 & 4, 2 & 3 and between 2 & 4 no resistance was measured.  That means my coil is done, I reckons.  I have one on order and will test it once it arrive so I know what it is supposed to show.

 

Much appreciated on your thoughts about my issue.

 

Cheers!

[dirtrider]

1 hour ago, wbw6cos said:

Good morning dirtrider,

 

Thanks for the reassurance.    I got continuity beep between my 1 & 2, but also resistance.   Not sure what that was all about.   

 

Test probes between my 3 & 4 measured nothing.  Between 1 & 3, between 1 & 4, 2 & 3 and between 2 & 4 no resistance was measured.  That means my coil is done, I reckons.  I have one on order and will test it once it arrive so I know what it is supposed to show.

 

Much appreciated on your thoughts about my issue.

 

Cheers!

Morning William 

 

That sounds like way too many problem for one coil to have. To me it sort of points to a bad meter, or incorrectly set meter?  Is your meter on the 20 ohm RESISTANCE scale?

 

[wbw6cos]

Good morning dirtrider,

 

I will have to double check it when I get home today.  Between the 1 & 2 in photo, it read .5 on 200 ohms scale.   I thought it was lowest range, but cannot recall at the moment. There may have been a lower setting.  I switched the range to a higher setting for the other tests.  That info was from an internet video (I know, right?), but not shown on a coil exactly like mine, hence my query.

 

Either way, I will test it some more this afternoon.    I ordered one from beemerboneyard so I will compare it once it arrives.  

 

I started checking all I could for evidence of burning throughout fuses, relays, and harnesses associated with them and nothing.  I started with the coil, but plan to check  in the alternator area next.   Before this incident,  I installed new Autolite plugs and ran it back and forth to work the day before.  I did have to keep throttle on to keep it running til warmed up.  The day of the no-start, I turned the key on and the headlight did not come on.  I thought the load shed relay was going bad again.  It was the 2nd or 3rd one over the past 10 years, so I figured it was going out again.  I hit the starter and cranked it for a second and pop noise followed by whitish smoke.   I did not try it again.  Removed battery.

 

I put 12v on all of the relays and got the clicks.  No evidence of electrical burns either.    Fuses all tested good with continuity from meter.  Just attempting to trace down the root cause.   Not sure battery went bad due to this or happened at the same time. Starter cables clean and tight, with relatively newish OEM style replacement maybe 7 years ago. No visible electrical burns.

 

 

[dirtrider]

37 minutes ago, wbw6cos said:

Good morning dirtrider,

 

I will have to double check it when I get home today.  Between the 1 & 2 in photo, it read .5 on 200 ohms scale.   I thought it was lowest range, but cannot recall at the moment. There may have been a lower setting.  I switched the range to a higher setting for the other tests.  That info was from an internet video (I know, right?), but not shown on a coil exactly like mine, hence my query.

 

Either way, I will test it some more this afternoon.    I ordered one from beemerboneyard so I will compare it once it arrives.  

 

I started checking all I could for evidence of burning throughout fuses, relays, and harnesses associated with them and nothing.  I started with the coil, but plan to check  in the alternator area next.   Before this incident,  I installed new Autolite plugs and ran it back and forth to work the day before.  I did have to keep throttle on to keep it running til warmed up.  The day of the no-start, I turned the key on and the headlight did not come on.  I thought the load shed relay was going bad again.  It was the 2nd or 3rd one over the past 10 years, so I figured it was going out again.  I hit the starter and cranked it for a second and pop noise followed by whitish smoke.   I did not try it again.  Removed battery.

 

I put 12v on all of the relays and got the clicks.  No evidence of electrical burns either.    Fuses all tested good with continuity from meter.  Just attempting to trace down the root cause.   Not sure battery went bad due to this or happened at the same time. Starter cables clean and tight, with relatively newish OEM style replacement maybe 7 years ago. No visible electrical burns.

 

 

Afternoon William

 

Load relief relay will NOT cause a no-start, it's main purpose is to turn the headlight off during engine cranking. 

 

Your meter needs to be on the 20K  setting, 13,000 ohms will probably not read if your meter is set to 200 ohms. 20K is 20,000 Ω, you need a meter setting that is over 13,000 Ω. 

[Jim Moore]

Hey DR,

 

A bike from the year 2000 will have a newer coil, right? 7,500 ohms?

[dirtrider]

8 minutes ago, Jim Moore said:

Hey DR,

 

A bike from the year 2000 will have a newer coil, right? 7,500 ohms?

Afternoon Jim

 

Probably so on the 1100R or RT but I'm not sure on William's 1200C, those things are very difficult to predict anything on. 

[wbw6cos]

It looked like the one shown on a parts fiche, with matching numbers.

[wbw6cos]

On the lowest scale (200 ohms) I tested primary side and got .5 ohms, BUT, on the 200 k ohms scale, I measured the secondary side (3 & 4 in pic) and the meter read 6.9 k ohms.  So I reckons the coil is fine.

 

Just for the sake of checking on why the battery had an issue, I used the meter to check continuity between both unattached battery cables and I got the beep.   That leads me to start looking down another path.  With the smoke coming from the frontal area, I am guessing it may be related to the alternator.  With just a look through the front and from the top area (moving the loosened electrical box) I cannot see any evidence of the spark or burn, but I cannot view the whole area yet.   I guess that will be for the weekend and possible another thread, if need be.

 

Thanks again, dirtrider!

[dirtrider]

2 minutes ago, wbw6cos said:

On the lowest scale (200 ohms) I tested primary side and got .5 ohms, BUT, on the 200 k ohms scale, I measured the secondary side (3 & 4 in pic) and the meter read 6.9 k ohms.  So I reckons the coil is fine.

 

Just for the sake of checking on why the battery had an issue, I used the meter to check continuity between both unattached battery cables and I got the beep.   That leads me to start looking down another path.  With the smoke coming from the frontal area, I am guessing it may be related to the alternator.  With just a look through the front and from the top area (moving the loosened electrical box) I cannot see any evidence of the spark or burn, but I cannot view the whole area yet.   I guess that will be for the weekend and possible another thread, if need be.

 

Thanks again, dirtrider!

Afternoon William

 

Yes the coil sounds OK (at least on ohm side) but I have seen a number of coils test OK on resistance but still have internal arcing. 

 

 Just for the sake of checking on why the battery had an issue, I used the meter to check continuity between both unattached battery cables and I got the beep.   That leads me to start looking down another path. ----   That is normal as there are a number of circuits that don't totally shut down until open. 

[wbw6cos]

Good afternoon dirtrider,

 

That makes sense about the coil; I did not know that about the battery cables (yikes.)   I have a good (used) coil in transit from BB, so we shall see.

 

In the mean time, is it possible to test the coil with a 12v source while it is not on the bike?  I would rather do it in a controlled setting before calling it good and reinstalling.

[dirtrider]

1 hour ago, wbw6cos said:

Good afternoon dirtrider,

 

That makes sense about the coil; I did not know that about the battery cables (yikes.)   I have a good (used) coil in transit from BB, so we shall see.

 

In the mean time, is it possible to test the coil with a 12v source while it is not on the bike?  I would rather do it in a controlled setting before calling it good and reinstalling.

Evening William

 

What are you after with testing the coil? 

 

I haven't ever tested the BMW coil off-bike but it probably could be done. 

 

Remove both spark plug wires then plug into coil. Next,  install a spark plug in each plug wire then hose clamp the spark plug bases together (it is  a lost spark coil so it sparks in a complete loop through both spark plugs).

 

Then hook a 12v battery (+) post to the coil's #2  primary terminal, then run a long wire from the coil's #1 primary terminal (wire needs about a 1/4" bare wire on the non coil end. 

 

Now quickly scratch the bare end of that long wire across the battery's negative post  (scratch it across the post long enough to allow the coil's primary to charge). You should see a spark across both spark plug electrode gaps as the wire scratches off of the battery's negative post & the coil's primary collapses.  

[wbw6cos]

Evening dirtrider,

 

Just curious to see if it will spark, or not.  You mentioned that coils test good with resistance, but still can arc internally.  My theory was to test it in a way to see if I can duplicate the issue with smoke.  Trying to eliminate things.  No worries.  I may try something with it, or maybe not.  I will continue investigating over the weekend.  

 

I appreciate your input, which points me in a better direction.  Definitely a better direction.

[dirtrider]

12 hours ago, wbw6cos said:

Evening dirtrider,

 

Just curious to see if it will spark, or not.  You mentioned that coils test good with resistance, but still can arc internally.  My theory was to test it in a way to see if I can duplicate the issue with smoke.  Trying to eliminate things.  No worries.  I may try something with it, or maybe not.  I will continue investigating over the weekend.  

 

I appreciate your input, which points me in a better direction.  Definitely a better direction.

Morning William

 

Even if your coil is bad (failed) then smoke coming from a BMW coil would be extremally unlikely.  About the only way a BMW boxer coil could smoke is if the Motronic failed therefore holding the coil's primary low-side pulled low for a very long time.

 

Just about any 12v circuit can smoke at a terminal connection if there is a load on the circuit & the terminal connection has poor connection due to resistance (terminal will usually be burnt brown or black when inspected).

 

Don't discount a poor connection at the headlight bulb, I have seen a few of those smoke a bit due to high resistance in the terminal connection.   (does you headlight come on at full brightness with key on?)

 

Another thing to look at is: What isn't presently working? If something isn't working, or is dim or intermittent, then that is a good place to look.

 

There are some hidden splices in your wire harnesses that can cause issues & those are very difficult to find if failed (unless something actually quits working). 

 

The typical place I see smoke after trying to start a BMW boxer is from the battery cables to battery post connections as that is a very high load carrying junction.  

 

Are you sure it was electrical smoke & not water vapor burning off, or combustion smoke seeping from an exhaust seam or pin hole? Electrical smoke is usually very pungent smelling. 

[wbw6cos]

Ah, thanks for giving me another thing to check  - headlight.  It is an Eagle Light after market LED, plug-n-play.  Doubtful, but will check.

As far as the moisture, I originally thought it was gas leaking from tank, which was repaired last summer due to a leak at seam near the left frame mount, but that was lower end and opposite of found moisture.    It did not smell like gas and that tank has been sitting with no leaks visible.  Vent tube not blocked. Over-flow line free of clogging. 

 

Definitely will look for arcing at connectors and pinched wires.  

 

Good feedback.  Thank you!

[Miguel!]

wbw6cos: In your opening post, you stated: "Coincidentally,  5 year old PC680 battery was hot, which I disconnected.    It tested 11.39 v the next day and the battery was swollen and hard to pull out of the battery tray without prybar action."   Personally, I'd have just started by replacing the battery and then start diagnosing from there. 

 

I don't think I can help you with much of your problem  but I do know a few things about electricity and electronics tho I'm not much of a wrencher and don't have much experience around vehicle diagnostics. But if I saw smoke and suspected that I'd burnt something up, I'd use my nose to start smelling for burnt electronics or wire. They have a very distinctive smell and you are either familiar with those smells or not. If you are, it might help you find the part that possibly smoked. If you aren't familiar with those smells, 🤷. Also, when you are snooping around, look for parts that my be "blistered" or deformed. Sometimes when something electrical fails, the packaging shows some evidence of the failure.

 

Please keep us informed. 

Miguel

[wbw6cos]

Will do.  Thanks Miguel!  Either that 5 year old battery was the cause or an effect of electrical issue.   

 

Yes, more investigating needs to be done.   I have a jump box that I may sub until the new battery arrives, but I want to visually check on things before hooking up.  The bike is mostly apart, but I will need more time to look deeper.   

 

With all the advice posted, I do not want to leave folks hanging.  Especially, You Know Who!  

 

Spoiler

The Oracle!  That's who.

 

[Miguel!]

There are lots of things about batteries I don't know but your measured voltage seemed low so I looked up a few things. This from Revzilla. I don't know if these values are valid for the PC680 tho. Miguel

 

[wbw6cos]

I am not sure if you noticed the battery in my photo (way up there) but below are some pics showing the below the boat anchor status of the battery.   Yeah, gone.   I traded it in for a newer model.  LOL

[dirtrider]

7 minutes ago, wbw6cos said:

I am not sure if you noticed the battery in my photo (way up there) but below are some pics showing the below the boat anchor status of the battery.   Yeah, gone.   I traded it in for a newer model.  LOL

 

 

 

Afternoon William

 

That battery looks more like it was damaged from improper mounting, or improper hold down in the battery box than by battery heat damage. Something distorted parts of it inwards, usually excess battery heat, or plates expanding bulges the  battery case.

 

That isn't to say that your battery is still good though.  

[wbw6cos]

Good morning,

 

Here is another interesting piece to the puzzle. I pulled the starter out and found evidence of arcing.  

Can I bench test this with a jump box to see of it was the cause?

 If so, briefly touch the 2 posts?

 

Other than that,  I did not find anything amiss elsewhere.  May just order a new starter and be done with it.   

 

It appears that the positive cable touched the casing, somehow.   WTH?

 

 

[dirtrider]

26 minutes ago, wbw6cos said:

Good morning,

 

Here is another interesting piece to the puzzle. I pulled the starter out and found evidence of arcing.  

Can I bench test this with a jump box to see of it was the cause?

 If so, briefly touch the 2 posts?

 

Other than that,  I did not find anything amiss elsewhere.  May just order a new starter and be done with it.   

 

It appears that the positive cable touched the casing, somehow.   WTH?

 

 

 

 

Morning  wbw6cos

 

That is a strange place for arcing, did that happed when trying to jump  the starter solenoid in place & tool slipped? Or possibly the removed battery cable touching it by mistake? 

 

You can bench test the starter --- 12v power to B+ post on starter,   ground to starter case,   then jump solenoid pull-in terminal to the B+.  terminal.

 

[Skywagon]

If you bench jump it hold on or clamp down. It will walk pretty hard

[wbw6cos]

Good morning dirtrider,

 

Nothing I did (I think) previously that would have caused that.   I never messed with the starter, other that removing the cover to look at it.   The cable must have moved, somehow, when  I had the battery disconnected last November when I removed the HES for testing; I had a hard start issue (different issue) that I was trying to work through - possible fuel or spark.  The only thing I can think of is if the cable got pulled too hard.   I did find part of black plastic from near where it arced.  Maybe from  the heat from the issue caused it to melt.   Like I said, I never worked on that area, so it must have gotten out of postion.  Dang gremlins.

 

I just ordered a starter from BB, so I will install once it arrives.  In the mean time, I may play around with the starter a little for possible rebuild or trash donation.

 

Thank you.

[dirtrider]

5 minutes ago, wbw6cos said:

Good morning dirtrider,

 

Nothing I did (I think) previously that would have caused that.   I never messed with the starter, other that removing the cover to look at it.   The cable must have moved, somehow, when  I had the battery disconnected last November when I removed the HES for testing; I had a hard start issue (different issue) that I was trying to work through - possible fuel or spark.  The only thing I can think of is if the cable got pulled too hard.   I did find part of black plastic from near where it arced.  Maybe from  the heat from the issue caused it to melt.   Like I said, I never worked on that area, so it must have gotten out of postion.  Dang gremlins.

 

I just ordered a starter from BB, so I will install once it arrives.  In the mean time, I may play around with the starter a little for possible rebuild or trash donation.

 

Thank you.

Morning  wbw6cos

 

It's also possible that someone dropped a socket or tool down in that area & that caused the arcing. (just a strange place to have an arcing short)

[wbw6cos]

Good afternoon dirtrider,

 

That someone would only be me, which is possible.  There are always extras leftover after I work on things.  

 

I will allow more slack in that cable and ensure that I get some heat shrink around that portion to insulate it if need be.   I will have to check the alignment and angle on that wire before I tighten things up.

 

The replacement starter is on order and the battery was ordered last week; I hope it will be in soon.  The wait continues.

[The Rocketman]

17 minutes ago, wbw6cos said:

There are always extras leftover after I work on things.

Good thing you didn't choose being a surgeon as your career.

[wbw6cos]

Good morning,

Update:

I tested the old starter and nothing happened.  It makes me think that the solenoid got toasted.  Inside was a little dirty, but good overall. 

I received my new starter from BB and the positive cable is still to close to the solenoid housing.  It is my belief that the heat from the original issue may have caused the cable and connector to flex enough for contact, or that happened afterwards.  I covered the metal portion of the connecter to prevent contact.  I also bent the end to allow clearance, Clarence.  We shall see how that works out once I install the battery, which is still on order.   Ugh.  

 

Cheers!

[wbw6cos]

Just to close out this thread, once I got the new battery installed, I covered the end of the positive cable that is too close to the starter housing.  I used some heat shrink to prevent any arcing issues.  Not sure how it was shorted out in the first place, but the issue has been resolved.  New battery, new starter, same coils, and no issues to report.

 

Thanks for all the feedback and helpful postings.

 

Cheers,