Electrical System Issues - Expert Advice Requested


Information and questions on GL1100 Goldwings (1980-1983)
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rkmason
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Electrical System Issues - Expert Advice Requested

Postby rkmason » Sun Dec 07, 2014 12:26 pm



Just fired up my '81 GL1100I first time yesterday out of it's 18 year slumber. It's running, but only on 2cyls I think. I suspect electrical/ignition issues. Sparkplug arcing appears very weak if at all.

OK, now the electrical issue that has my immediate attention. When the motor is running, as I bring up the rpm the headlight starts to dim and both turn signal indicators on the instrument panel start to illuminate. I have tried running with the in-harness diode removed (no effect) and the generator disconnected (no effect). If I flip the engine kill switch while the engine is at high rpm the headlight flicker stops and the turn signal indicators go out. Guess I should check the ignition coils primary resistance next. I tested the in-harness diode (correctly this time with the multimeter diode test function) and it reads 510mV voltage drop forward biased and open circuit when reverse biased so I think it's working properly.

Anybody got any other ideas?


Last edited by rkmason on Sun Dec 07, 2014 1:38 pm, edited 1 time in total.

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HawkeyeGL1200
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Re: Electrical System Issues - Expert Advice Requested

Postby HawkeyeGL1200 » Sun Dec 07, 2014 1:34 pm

No expert here... but a couple of observations none the less... there have been multiple strange electrical phantoms that appear to be rooted in the dogbone fuse and imminent failure of same. Some of the symptoms seem to make absolutely no sense at all when you think about how something as simple as the replacement of a fuse, either with a direct replacement or by replacing the entire fuse holder and fuse with a more modern "automotive" style fuse.. that I'd be tempted to look there as the root to your electrical spurious issues...

Another place I'd look is battery, solenoid, and "other" electrical connections, both "hot" and "ground" wires to make sure that 18 years of idleness haven't set up some corrosion that is making it difficult for current to pass, making your coils and other electrical devices function in a way adverse to a proper running motorcycle. If you're sure your carburetors aren't contributing to the poor running of the engine, then I'd focus on connections, and then your poorly running bike.

You can run it for a short period of time, like 10 seconds, then shut it off and then tap the header pipes to see which cylinders are not working. If it's one on each side (like the two "fronts" or the two "rears") then it could be a coil. If it's both cylinders on one side of the engine, then I'd suspect a fuel problem.. since 1/2 and 3/4 share a coil... it would be odd for it to be both on the same side of the engine or one front and one rear, and have it be a coil problem.

I'm sure someone with more electrical savvy will respond soon. I just find these bikes to be fairly simple to trouble-shoot if you break the way it operates down into the simplest of parts. ... I hope you get the bugs worked out soon, so you can enjoy riding her again.
I am wrong as often as I am right concerning what is wrong with someone else' motorcycle without having seen the machine in person. Guessing with limited information, as to the source of the trouble, is sketchy at best.

rkmason
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Re: Electrical System Issues - Expert Advice Requested

Postby rkmason » Sun Dec 07, 2014 2:03 pm

HawkeyeGL1200 wrote:No expert here... but a couple of observations none the less... there have been multiple strange electrical phantoms that appear to be rooted in the dogbone fuse and imminent failure of same. Some of the symptoms seem to make absolutely no sense at all when you think about how something as simple as the replacement of a fuse, either with a direct replacement or by replacing the entire fuse holder and fuse with a more modern "automotive" style fuse.. that I'd be tempted to look there as the root to your electrical spurious issues...

Another place I'd look is battery, solenoid, and "other" electrical connections, both "hot" and "ground" wires to make sure that 18 years of idleness haven't set up some corrosion that is making it difficult for current to pass, making your coils and other electrical devices function in a way adverse to a proper running motorcycle. If you're sure your carburetors aren't contributing to the poor running of the engine, then I'd focus on connections, and then your poorly running bike.

You can run it for a short period of time, like 10 seconds, then shut it off and then tap the header pipes to see which cylinders are not working. If it's one on each side (like the two "fronts" or the two "rears") then it could be a coil. If it's both cylinders on one side of the engine, then I'd suspect a fuel problem.. since 1/2 and 3/4 share a coil... it would be odd for it to be both on the same side of the engine or one front and one rear, and have it be a coil problem.

I'm sure someone with more electrical savvy will respond soon. I just find these bikes to be fairly simple to trouble-shoot if you break the way it operates down into the simplest of parts. ... I hope you get the bugs worked out soon, so you can enjoy riding her again.


Yeah, I was wondering if that main "dogbone" fuse could be the problem, but I found that a PO already replaced the OEM fuse with a std automotive 30A fuse so no joy there.

I recently completed a total rebuild of the carb set so I am going to assume for right now it's not a fuel issue just to narrow down my area of investigation. The symptoms I see certainly don't support this being a fueling problem.

Think I'll investigate the flaky electrical connections angle as you suggested. I already saw a bit of this type problem getting the starter to operate. I was about to replace the starter solenoid but found that a simple unplug/replug of the 4pin connector on the solenoid magically made the starter begin working.

Thx for the suggestions.

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HawkeyeGL1200
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Re: Electrical System Issues - Expert Advice Requested

Postby HawkeyeGL1200 » Sun Dec 07, 2014 2:45 pm

One other thing comes to mind. Have you had a good look at the stator to rectifier/regulator connectors (the three yellow wire connector just ahead of the battery) to make sure they're not corroded badly? Most old-Goldwing owners hard-wire the stator to R/R as poor contact at the connector can lead to premature stator failure, and this could alter input voltage to the R/R and possibly mess up your charging system...
I am wrong as often as I am right concerning what is wrong with someone else' motorcycle without having seen the machine in person. Guessing with limited information, as to the source of the trouble, is sketchy at best.

rkmason
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Re: Electrical System Issues - Expert Advice Requested

Postby rkmason » Sun Dec 07, 2014 8:45 pm

HawkeyeGL1200 wrote:One other thing comes to mind. Have you had a good look at the stator to rectifier/regulator connectors (the three yellow wire connector just ahead of the battery) to make sure they're not corroded badly? Most old-Goldwing owners hard-wire the stator to R/R as poor contact at the connector can lead to premature stator failure, and this could alter input voltage to the R/R and possibly mess up your charging system...


The three pin generator stator connector looks ok. I even ran the bike with this plug disconnected - no effect.

I just measured the two coils primary resistances at the three pin connector for the coils 12V primary power and ground lines. I get a net resistance of 2.4 Ohms for each of the coil primaries (3 Ohm measurement minus .6 Ohm test lead resistance). That is apparently much higher than the .4 Ohm coil primary spec. If it's real it could account for weak spark arcs but I'm not convinced yet that is the problem. I'll pull the coils and measure again directly at the coil primary terminals to be sure.

Can anyone tell me where the wiring ground attachment points are located on the frame? I want to check/clean them all. The schematic shows 2 frame wiring ground points other than the battery and starter grounds.

Is there any way to bench test or otherwise check the coil ignitor units for correct operation?

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Re: Electrical System Issues - Expert Advice Requested

Postby WingAdmin » Mon Dec 08, 2014 10:27 am

rkmason wrote:Just fired up my '81 GL1100I first time yesterday out of it's 18 year slumber. It's running, but only on 2cyls I think. I suspect electrical/ignition issues. Sparkplug arcing appears very weak if at all.

OK, now the electrical issue that has my immediate attention. When the motor is running, as I bring up the rpm the headlight starts to dim and both turn signal indicators on the instrument panel start to illuminate. I have tried running with the in-harness diode removed (no effect) and the generator disconnected (no effect). If I flip the engine kill switch while the engine is at high rpm the headlight flicker stops and the turn signal indicators go out. Guess I should check the ignition coils primary resistance next. I tested the in-harness diode (correctly this time with the multimeter diode test function) and it reads 510mV voltage drop forward biased and open circuit when reverse biased so I think it's working properly.

Anybody got any other ideas?


It sure sounds like you've got a grounding issue. Where that grounding issue is occurring is the question.

We can probably confirm it by running the engine up to RPM where the headlight starts to dim and the turn signals illuminate. When you've done this, press the horn (which will provide more ground). If the headlight brightens and the turn signals illuminate, we can pretty much guarantee the problem is a bad ground somewhere.

rkmason
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Re: Electrical System Issues - Expert Advice Requested

Postby rkmason » Mon Dec 08, 2014 10:46 am

WingAdmin wrote:It sure sounds like you've got a grounding issue. Where that grounding issue is occurring is the question.

We can probably confirm it by running the engine up to RPM where the headlight starts to dim and the turn signals illuminate. When you've done this, press the horn (which will provide more ground). If the headlight brightens and the turn signals illuminate, we can pretty much guarantee the problem is a bad ground somewhere.


There may be more than one problem here. I am going to check/clean the grounds, but I also may have a separate issue with the ignition coils. I pulled the coil asm out of the frame and measured the primary resistance right at the coil primary connections. Both coils are measuring 2.3 - 2.4 Ohms (net measurement after subtracting test lead resistance). This is much higher than the OEM Spec of .4 Ohm and would account for a very poor spark output. Can someone verify that the correct coil primary resistance actually measured is ~.4 Ohm ('81 coil ID AW82-TRI) ?

I found one of the wiring frame ground points under one of the coil asm attachment points; where is the other wiring frame ground shown on the schematic?

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Re: Electrical System Issues - Expert Advice Requested

Postby Phavas » Mon Dec 08, 2014 11:16 am

Run a supplementary groun from the battery to the frame via an engine mount.
If your light dims when the engine is running, then the battery is not keeping up with the discharge -
either through resistance (ground) or poor charging amperage, or a defective battery (plates shorting under load)
Do a load test on the battery and a loaded charge test on the alternator.
If they both are OK, then it has to be a resistance (corrosion) issue.

Cheers,
Zaphod
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rkmason
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Electrical System Issues - Fixed

Postby rkmason » Thu Dec 11, 2014 3:57 pm

I have now banished my electrical gremlins back to wherever they came from. Here is what I found and fixed:

The headlight/turn signal electrical issues were caused by poor grounding between the fairing electrics and the rest of the bike. The way my bike was wired the only ground path for all of the in-fairing electrics was thru the fairing mount screws into the metal fairing support structure and across to the main frame. This ground path had gone high resistance due to corrosion leading to my light problems.

Interestingly, I found that my bike's wiring out into the fairing is not as shown on the schematic. There is no primary ground wire passing thru the main electrical services plug out to the fairing as the schematic shows. I have now added a supplemental ground wire from the main wiring junction box underneath the instrument panel out to the headlight power plug. That's a much more reliable ground path for the in-fairing electrics than using the fairing support structure and bike frame.

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Re: Electrical System Issues - Expert Advice Requested

Postby HawkeyeGL1200 » Thu Dec 11, 2014 6:33 pm

I'm very glad to be reading that you're issues have been solved and resolved... a lot of times folks who ask questions don't provide feedback on how things work out, and (I can't speak for anyone else) I'm often left wondering if anything I wrote helped or even made the problem worse... Good detective work you did on your end to chase that problem to ground (pun intended)...

Happy trails!
I am wrong as often as I am right concerning what is wrong with someone else' motorcycle without having seen the machine in person. Guessing with limited information, as to the source of the trouble, is sketchy at best.

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Re: Electrical System Issues - Expert Advice Requested

Postby Phavas » Thu Dec 11, 2014 6:36 pm

Thanks for your feedback, I'm glad Hawkeye was right... and Wingadmin...

Cheers,
Zaphod
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Re: Electrical System Issues - Expert Advice Requested

Postby rkmason » Thu Dec 11, 2014 7:17 pm

Yes, I think the most informative threads on forums like this are the ones that contain both the problem and the fix. Or as somebody used to say - "the rest of the story"

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Re: Electrical System Issues - Coil Primary Resistance

Postby rkmason » Fri Dec 12, 2014 11:16 am

rkmason wrote:I just measured the two coils primary resistances at the three pin connector for the coils 12V primary power and ground lines. I get a net resistance of 2.4 Ohms for each of the coil primaries (3 Ohm measurement minus .6 Ohm test lead resistance). That is apparently much higher than the .4 Ohm coil primary spec. If it's real it could account for weak spark arcs but I'm not convinced yet that is the problem. I'll pull the coils and measure again directly at the coil primary terminals to be sure.


I just got new replacement coils (not OEM) and their primary circuit resistance is the same as my current OEM coils (~2.4 Ohms) Either my measurements are faulty somehow or the actual coil primary resistance has never been the Honda spec value (.4 Ohm). Has anyone else measured their working coils primary resistance?

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Re: Electrical System Issues - Coil Primary Resistance

Postby HawkeyeGL1200 » Fri Dec 12, 2014 12:18 pm

I was hoping one of the smart guys would answer your primary resistance question, to keep me from writing something (else) stupid here, but it's Friday and I can't control myself.

I don't recall if you ever established which cylinders were acting up. I know resistance in coils, within reason, is important, however I'm thinking there are resisters in the spark plug boots and there's probably a ballast resister in-line with the feed to the coils, and I guess my point is, are you sure your coils have anything to do with why your engine isn't running properly in the first place??

If two cylinders aren't firing and they're 1/2 or 3/4 and I have poor spark, then I'd look to coils.. if they're 1/3 or 2/4 or 1/4 or 2/3 then I'd definnitely turn my attention elsewhere... not that there isn't anything wrong with your coils... but I'm always leaning toward determination of the root of the problem first... Did you determine your spark is weak by looking at the arc across the plug gap? If that's the case, are the resistor screws in the plug boots tight? Are the plugs the correct make and model for the engine? Are the wires in good shape... and I know you probably know more about this sort of thing than me, because you're looking into coil resistance, which I can honestly tell you I've never measured in my life...

Since you found poor grounds to your fairing, it makes me wonder if the power supply to the coils isn't involved in some way... positive or grounds not making up like they should... you know, simple stuff that a simple guy like me would be able to decipher without a VOM...

I know there was some discussion some where about using a coil out of a 4-cylinder automotive engine (maybe a Neon coil) and a great discourse on resistance broke out... I can't remember where I read about it or how the discussion resolved itsself other than to say that in some applications, the ballast resistor was included in the circuit to protect the electronics in the ECM, which I do not believe we have on these 1100's... and as to whether more primary coil resistance is good or bad, I'll hope that ADMIN chimes in, as he's a VERY smart electronics guy and I am not... back to work for me... I hope you figure it out so I can learn more about coils

rkmason wrote:I just got new replacement coils (not OEM) and their primary circuit resistance is the same as my current OEM coils (~2.4 Ohms) Either my measurements are faulty somehow or the actual coil primary resistance has never been the Honda spec value (.4 Ohm). Has anyone else measured their working coils primary resistance?
I am wrong as often as I am right concerning what is wrong with someone else' motorcycle without having seen the machine in person. Guessing with limited information, as to the source of the trouble, is sketchy at best.

rkmason
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Re: Electrical System Issues - Expert Advice Requested

Postby rkmason » Fri Dec 12, 2014 3:59 pm

Sorry, I failed to update this thread with my findings relative to my misfiring cylinder problem. I sprayed some starting fluid into each carb throat with the engine running and found that my problem is lack of fuel delivery from the cyl #3 carburetor. The engine runs smooth temporarily using the starting fluid so obviously all cylinders have spark. I still have to dig into the #3 carb problem.

My leftover question here is why a good coil measures much higher primary resistance than what the OEM spec says. I was aware of the previous discussion thread around use of a ballast resistor either contained within the ignitor units or as a separate inline resistor, but no mention of use of coils with primary resistance much higher than spec. I have now verified my resistance measurements are valid using a 2nd meter

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Re: Electrical System Issues - Expert Advice Requested

Postby Phavas » Sat Dec 13, 2014 6:40 am

Do a compression test on tha cylinder first. You may have a burned valve
One of your coils may be badly grounded or on the way out. Were they hot or cold when you tested them?
Cheers,
Zaphod
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blake46201
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Re: Electrical System Issues - Expert Advice Requested

Postby blake46201 » Sat Feb 07, 2015 5:39 pm

Hello , i would lead toward the regulator and its connections , check your overall voltage running back into the battery , i had the same type of issues replaced the stator and still had the problem , hope this helps

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Re: Electrical System Issues - Expert Advice Requested

Postby rkmason » Sat Feb 07, 2015 11:06 pm

blake46201 wrote:Hello , i would lead toward the regulator and its connections , check your overall voltage running back into the battery , i had the same type of issues replaced the stator and still had the problem , hope this helps

Nope, regulator operation and stator connections were fine. My issues boiled down to two items:

(1) Two of my newly rebuilt carbs still had plugged up slow jets. Once I removed and cleaned out the jets I had all four operating cylinders instead of two. I had a fully functioning ignition system the whole time.

(2) I found a high resistance ground path for the front fairing electrics making the front lights act funny. Fixed this issue by running a supplemental ground wire from behind the headlight back to the main wiring junction in the box behind the front fork inertia weight. The original fairing lights ground path went thru the left side radio mount plate into the fairing mounting structure and then the frame. A poor ground path design IMHO




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