Rebuild 1978 Gl1000 - Electrical Issues


Information and questions on GL1000 Goldwings (1975-1979)
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canadianpat
Posts: 5
Joined: Thu Aug 08, 2019 11:15 pm
Location: Niverville, Manitoba, Canada
Motorcycle: 1978 Honda Goldwing GL1000
1979 Honda Silverwing 500
2009 Suzuki GS500

Rebuild 1978 Gl1000 - Electrical Issues

Post by canadianpat » Sun Aug 18, 2019 11:16 am



Good day Goldwingdocians. I'm new to the Goldwing Docs group and new to goldwings :-)

Picked up an 1978 Goldwing in non running condition in hopes to get it running and then restore it or at least get it safetied and cruisable.

Wing is in decent looking condition but with 80,000 kms.

First thing I wanted to check was the electrical/ignition system. Found out had no spark. Been reading through many forums and getting acquainted with the bikes systems.

What I've done so far not necessarily in the right order.

1. Contacts:
- Cleaned the contacts as they were not grounding properly
- I still get a bit of voltage when they are in contact. 1-2 volts on the one side, can't remember the other side will check that again.
- I have to verify the contact sides as I think I was getting some grounding on both wires when I was closing the one contact (which I imagine shouldn't be happening, figured each side should be isolated)

2. Pre Coils: From Contacts to coil connectors at harness
- Confused a bit as the connector from harness to coils has 6 wires vs the wiring diagram showing 4. I have the Blue&Yellow (coming from contacts), 2-Black/white (from kill switch according to diagram), 1 yellow HR (heat rated wire), 1 - black HR (heat rate wire)
- I get 12 Volts at the yellow & black HR wires with kill switch off. With kill switch on I get 11 volt on Yellow HR & 4.5volts Black HR
- White black wires both have roughly 4.5 Volts with kill swith on and ignition on. When holding start button (engine cranking) they jump up to 7-7.5 Volts
- The Yellow wire gets some voltage (ranges between 2 to 7 volts) when cranking.
- The Blue wire gets some voltage (ranges between 2 to 7 volts) when cranking.
- I imagine the yellow and blue wires voltages are due to open or closed points, and the reader can't be accurate as the voltage changes quickly

3. Post Coils: Cables, caps and plugs
- Found that almost all caps were not getting great contact, cut back 1/4-3/8" of cable and redone all of them.
- 1 Cap had fried resistor and is non repairable, so will get a new one.
- checked resistance across spark plugs and seems to be that all 4 are fried
- after repairing wires & caps, Now getting proper resistance across coils (tested with the coils disconnected from the main harness)

The last thing I've done so far is grabbed a spark plug from a similar year silver wing (completely different plug) that I'm also working on that was good (tested the plug which had proper resistance). I just wanted to use the plug to see if I got spark now that I've done a couple things on the bike (test method just slight touching the engine body) it sparked real good for about 4 to 5 rotations then it stopped and seems that the plug is fried. 2 conclusions to this test either the plug was not rated for what the Gold Wing puts out (doubt it would wreck a plug with just a couple turns) or there is something majorly wrong with the voltage going through the coils.

I don't know if the information I've provided in some beginning diagnosing would help any of you determine where I should be looking next or if I'm testing these correctly. I'm hoping I can try to isolate the problem before I go spend a bunch of money ordering parts that I don't need. Also don't want to go buy plugs just to find out that I'm going to fry them all just testing it out.

Thanks for any help you can provide. Sorry for the long message.



canadianpat
Posts: 5
Joined: Thu Aug 08, 2019 11:15 pm
Location: Niverville, Manitoba, Canada
Motorcycle: 1978 Honda Goldwing GL1000
1979 Honda Silverwing 500
2009 Suzuki GS500

Re: Rebuild 1978 Gl1000 - Electrical Issues

Post by canadianpat » Wed Aug 21, 2019 12:26 am

If this post is in the wrong section please let me know.

canadianpat
Posts: 5
Joined: Thu Aug 08, 2019 11:15 pm
Location: Niverville, Manitoba, Canada
Motorcycle: 1978 Honda Goldwing GL1000
1979 Honda Silverwing 500
2009 Suzuki GS500

Re: Rebuild 1978 Gl1000 - Electrical Issues

Post by canadianpat » Sat Aug 31, 2019 4:42 pm

Did I provide to much information? Any help would be awesome.

Old Fogey
Posts: 818
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1979 GL1000
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Re: Rebuild 1978 Gl1000 - Electrical Issues

Post by Old Fogey » Sun Sep 01, 2019 5:27 am

Electrical problems are the ones most folk shy away from!
I'm no electrical guru but I will try to help. One section at a time. Right now I can only access the USA wiring diagram for that year; not sure if yours is US or Canadian nor if in fact there is any difference. The main difference between US and Euro is the permanently on headlight on US models.

Here is good enlargable diagram, not sure but you may need to join NGW to see it.
https://www.ngwclub.com/gallery3/var/al ... 1389594810

1) don't know where at this point you are getting the current for voltage reading but yes, the two sets should be isolated from each other. In fact, view the system as three individual circuits. 2 of one coil, one contact breaker, one side of the condenser, 2 HT leads, 2 caps, 2 plugs. Plus 1 of battery, harness, ignition switch, Run switch, resistor block on coil bracket.

2) this bit confuses me. You say you have 6 wires from harness but only note 5.
You should have:
2 white/black which are the feed for the coils coming from the Run switch. Withignition on, Run switch off, there should be nothing reading on them. With Run on each should read 7 volts normal, 12 volts with the starter button pressed ( the resistor gets bypassed to allow full voltage for starting).
1 yellow/blue coming from points through condenser to one coil
1 yellow coming from points through condenser to the other coil
1 black and 1 brown/black to the resistor

3) Check out my tip on plug caps (and the rest of my Tech Tips while you are at it!) http://wingovations.com/plug-cap-corrosion/4579471118
Don't know why any spark plug would burn out like that! Certainly not with standard 40 year old GL1000 coils! I have a direct wired full Dyna electronic system on my GL1000 with a spark like a welding torch and I don't burn out plugs.

I hope this helps a bit. I chased ignition gremlins for ever on mine. Eventually gave up and converted to the system I have now.
'Impossible' is just a level of difficulty! The only stupid question is the one you didn't ask first!

( Seriously, you haven't read all 115 pages of my http://www.wingovations.com website ?? :shock: )

canadianpat
Posts: 5
Joined: Thu Aug 08, 2019 11:15 pm
Location: Niverville, Manitoba, Canada
Motorcycle: 1978 Honda Goldwing GL1000
1979 Honda Silverwing 500
2009 Suzuki GS500

Re: Rebuild 1978 Gl1000 - Electrical Issues

Post by canadianpat » Sun Sep 01, 2019 2:01 pm

Thanks for this info/help. I have been doing further testing. I understand the Schematic a bit better didn't realize the Black bars/rectanlges were indicating a connector. So now I understand that The Black and The Black brown wires are for the resistor which is mounted right behind the coils.

I'm certainly getting closer and starting to understand the system a lot better.

I think either the resistor or the coils have something going on, or the have something wrong in the wiring/connectors that is back feeding or bad grounding....

So started checking a couple things... with everything plugged in as it's supposed to be I am getting 4.5 Volts on both Black White wires and 7.5 Volts when the starter button pressed. When engine stop switch is turned off there is nothing at the 4 coil wires. I've tested the stop switch to make sure it wasn't faulty but seems as though it's good. When the stop switch is off I have 12 volts on the one side and nothing on the other. When it is turned on I get 4.5 Volts on both sides (which I know doesn't sound right but keep reading and you'll see what I mean by thinking it is fine).

I then disconnected the contacts & the condensor thinking it might be something on that side of things that is shorting out. So with the contacts and the condensor disconnected & ignition & engine stop switch is in on/run position I get 11.8 - 12 volts on all 6 wires at the connector. Getting 12 volts on both sides of the stop switch when turned on and as it should has 12 volt one side and nothing on the other when it's in the off position (thus my thinking the switch is fine).

I tried everything hooked up except the condensor, but still the same 4.5 volts and 7.5 when start button is pressed.

I then tested the points for continuity. So disconnected their wires from the whole system and tested accross and only on 20,000K setting do I get a OHM reading of maybe 800 accross the 2 points (my thinking is this is likely just general feedback unless I'm wrong and this is supposed to be completely isolated even at 20,000k setting)? but for general OHM settings I get grounding connectivity across the respective closed point as I think it should and nothing on the open point. So that seems to be fine to me (also note I cleaned the points and adjusted the point gaps to .35mm before all this testing).

What I did find odd is when everything connected if the Yellow side point was closed I would get roughly 0.15 volts on the yellow wire (which is maybe feedback) and 4.5 volts on the 2-black/white, the blue/yellow & the black brown (resistor) but 11.3 volts on the Black (resistor) wire. When the blue/yellow side point was closed everything was the same but reversed on the yellow & blue yellow wires (which makes sense and tells me the points are likely doing what they are supposed to depending if they are open or closed).

I'm a bit confused where to try and isolate the problem. I'm not sure why I get near 12 volts when points are disconnected (when it should be 7?) and get 4.5 volts when they are connected and only 7 when the start button is pressed (engine turning of course).

I hope this all makes a bit more sense. I'm usually very quick at figuring things out with this older motorized tech stuff but don't know the bike very well and just trying to head in the right direction.

I will keep working on it and test the continuity of each wire from the points up to the harnesses and so on, but everything looks in good shape so far in terms of connections and what not.

Old Fogey
Posts: 818
Joined: Fri Oct 30, 2009 2:09 am
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Motorcycle: 1976 GL1000
1979 GL1000
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Re: Rebuild 1978 Gl1000 - Electrical Issues

Post by Old Fogey » Sun Sep 01, 2019 2:55 pm

I must admit to reaching the end of my knowledge, but try bypassing the resistor by connecting the black and the black/brown together to see what happens. You should have 12v all the time at the points and the two black/white coil wires.

I'm also guessing that you may have a failed diode. This what they call resistor, sitting to the bottom left of the diagram , connected to the starter switch.
'Impossible' is just a level of difficulty! The only stupid question is the one you didn't ask first!

( Seriously, you haven't read all 115 pages of my http://www.wingovations.com website ?? :shock: )

canadianpat
Posts: 5
Joined: Thu Aug 08, 2019 11:15 pm
Location: Niverville, Manitoba, Canada
Motorcycle: 1978 Honda Goldwing GL1000
1979 Honda Silverwing 500
2009 Suzuki GS500

Re: Rebuild 1978 Gl1000 - Electrical Issues

Post by canadianpat » Sun Sep 01, 2019 3:09 pm

Thanks.

This diode you mention that is connected to the starter switch... did you meant what they call the rectifier with the orange yellow wire going in and black brown coming out.

Old Fogey
Posts: 818
Joined: Fri Oct 30, 2009 2:09 am
Location: Glasgow Scotland
Motorcycle: 1976 GL1000
1979 GL1000
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Re: Rebuild 1978 Gl1000 - Electrical Issues

Post by Old Fogey » Sun Sep 01, 2019 4:57 pm

My mistake, yes. I mistyped


'Impossible' is just a level of difficulty! The only stupid question is the one you didn't ask first!

( Seriously, you haven't read all 115 pages of my http://www.wingovations.com website ?? :shock: )

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