Fixed my electrical problem (headlights, dash lites,horn, turn signals, windshield)

dduelin

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60 miles from home yesterday the ground circuit problem happened again. The bike quit at a stop sign and from then on basically nothing electrical in the front half of the bike worked and the bike would not start with high beams on. The engine would start and run with the headlight dip switch on low beam although there were no headlights and I was able to ride it home. This problem is detailed in this earlier thread:

https://www.st-owners.com/forums/showthread.php?120747-Location-of-main-chassis-frame-ground-Ground-circuit-fault

When I got home I stripped off the tupperware and began reading all the threads again with similar problems. The ground wire out of the bottom of the 24 pin connector on the front left of the motorcycle above the cylinder head tested good continuity to the ground but because other similar problems with 1300s centered on this ground circuit I made a 14 gauge wire test lead with a pointed metal tip and inserted it into the plastic connector so it made contact with the connector's terminal for the green wire, bypassing the wire, and touched the other end to the frame while the key was on. All the lights came on brightly and the fuel pump spun up. Alright!!!!! To fashion a low resistance ground I cut the old ground wire in two and twisted and soldered a piece of the new wire onto it and crimped a ring terminal on the end. I grounded it to one of the 8 mm bolts that secure the left side coil.

Thanks to all of you that contributed in earlier threads I was able to get right to it and affect a repair.
 

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Scooter

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Re: Fixed my electrical problem (headlights, dash lites,horn, turn signals, windshiel

... I made a 14 gauge wire test lead with a pointed metal tip and inserted it into the plastic connector so it made contact with the connector's terminal for the green wire, bypassing the wire, and touched the other end to the frame while the key was on.
I'm going to assume that you inserted it into the lower portion of the connector where you ultimately made the splice, correct?

To fashion a low resistance ground I cut the old ground wire in two and twisted and soldered a piece of the new wire onto it and crimped a ring terminal on the end. I grounded it to one of the 8 mm bolts that secure the left side coil.

Glad you found a fix for this Dave. So if I interpret this correctly, the root cause is somewhere in the ground wire leading back from the 24-pin connector. Wish I had a spare wiring harness. It would be interesting to open it up and see how the ground wire is routed internally...
 
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dduelin

dduelin

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Re: Fixed my electrical problem (headlights, dash lites,horn, turn signals, windshiel

I'm going to assume that you inserted it into the lower portion of the connector where you ultimately made the splice, correct?




Glad you found a fix for this Dave. So if I interpret this correctly, the root cause is somewhere in the ground wire leading back from the 24-pin connector. Wish I had a spare wiring harness. It would be interesting to open it up and see how the ground wire is routed internally...
Yes, I inserted the test lead into the bottom part of the connector hoping to retain the full use of the connector rather than having to splice into the green wire above the connector. I would have done that though if the fault had been in or above the 24 pin connector. I hope this does really fix the original problem.
 

ST Gui

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Re: Fixed my electrical problem (headlights, dash lites,horn, turn signals, windshiel

the root cause is somewhere in the ground wire leading back from the 24-pin connector.
What direction is "back"? I understand that somewhere, a ground wire became less or completely separate or "ungrounded" from the frame or ground point. The added wire augmented or replaced (without having to find, access, correct) the troubled connection, if I interpret this correctly.

It apparently makes no difference what side of the connector had the failure. dd, did you test the continuity with the connector in place, or did you open the connector first?
 
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dduelin

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Re: Fixed my electrical problem (headlights, dash lites,horn, turn signals, windshiel

Back in this case means toward the rear of the bike. The green wire I cut in two eventually emerges from the thick bundle leading toward the rear and ends in a terminal that is bolted to the frame under the rear of the gas tank. That is the "end of the line" so to speak so the fault is apparently somewhere in the original bundle between the 24 pin connector and the terminal under the gas tank. Up in the front of the fairing just above the right headlight is a yellow connector that bundles a large number of ground wires into the one that leads to the upper side of the 24 pin connector. Some of the threads on this general subject indicate their fault was in the yellow connector above the headlight. To your second question ......... In my case I checked continuity on both sides of the connector but that was a red herring. Despite having good continuity with my Ancor multi meter the wire failed to pass enough current under load thus was replaced with a shorter thicker one to the frame under the coil mounting bolt.
 

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Re: Fixed my electrical problem (headlights, dash lites,horn, turn signals, windshiel

What direction is "back"? I understand that somewhere, a ground wire became less or completely separate or "ungrounded" from the frame or ground point. The added wire augmented or replaced (without having to find, access, correct) the troubled connection, if I interpret this correctly.
As Dave already answered, I meant back toward the rear of the bike. My guess is that there is a chafed or cut ground wire somewhere that might be down to one strand left intact on the wire. I always like to know what the root cause of somebody else's problem is. That way I can plan ahead or maybe implement some preventative measure to keep it from happening to me.

It apparently makes no difference what side of the connector had the failure. dd, did you test the continuity with the connector in place, or did you open the connector first?
Maybe you meant that he could have just as easily put the splice in on the other side of the connector (?). That certainly could be doable. Getting the problem resolved by putting the new ground splice in where he did proves that the problem is somewhere in the ground wire between the splice and the main ground connection at the frame by the gas tank. So moving that splice point up a couple of inches doesn't prove much other than we now know that the connector itself wasn't the issue.

What is interesting is that from the looks of the first picture and the way he described the repair it looks like to me that when he cut the ground wire into two, he only soldered the pigtail to the lead coming out of the connector and left the other end of the wire from the harness unconnected, which is fine. If he had made the repair on the other side of the connector in the same fashion, he would have had to make sure that the splice would have been made to the wire coming from the front of the bike and not the end coming from the connector (as I'm sure he would have :) )...
 

ST Gui

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Re: Fixed my electrical problem (headlights, dash lites,horn, turn signals, windshiel

Maybe you meant that he could have just as easily put the splice in on the other side of the connector (?).
No, I was wondering how he knew which side of the connector to cut. With the connector connected, there would be continuity on either side, at the connector. Pulling the connector apart would show which side had the open ground.

As dd said in this case it continuity as indicated by the meter didn't matter because there wasn't sufficient ground to complete circuits even though there was continuity.
 
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Re: Fixed my electrical problem (headlights, dash lites,horn, turn signals, windshiel

For checking a circuit like this in the future- a circuit where a simple continuity test showed ground, you can test for voltage drop. Set the multimeter to the appropriate DC Volts setting (usually 20v) and ground one probe to a known good point. With the key on and the circuits giving you problems turned on, start at one end of the ground circuit and test the ground wire for voltage. When you find more than a very slight change, you found the bad section of wire. In this case, you probably would have ended up with close to a 12v or higher reading on the ground wire.

Testing like this, the meter will be wired parallel to the ground circuit, but when you find the bad section of wire, the meter ends up as a bypass- essentially becoming wired in series instead of parallel.
 

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Re: Fixed my electrical problem (headlights, dash lites,horn, turn signals, windshiel

Pulling the connector apart would show which side had the open ground.
Not in this case. You need to look at the wiring diagram and then you will see that the ground wire is being routed through that connector to provide the ground to various items (lights, lamps, instrumentation, windshield and most importantly for Dave, the bank angle sensor, etc). Pulling apart the connector means none of those items in front of the connector are grounded. I suppose that Honda could have simply just tied all of those wires together and attached them to the frame up front but they choose not to do that, perhaps for ground loop issues.
 
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dduelin

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Re: Fixed my electrical problem (headlights, dash lites,horn, turn signals, windshiel

There was one other weird thing going on during the ride home with the bad ground and I'll throw it out there at no additional charge. While riding along with most of the electrical system on the fritz I flipped the engine stop switch to the off position in the off chance it was causing part or all of the problem and flipping on and off might clean a wonky contact. Of course the engine quit but I was doing 55 mph in 5th with the clutch out so when I flipped the switch back to run position I was surprised the engine did not come on. I thumbed the starter and magically the ignition came on and the engine came to life. I did this a few times just to verify that somehow the act of engaging the starter button brought the dead ignition system to life and then letting the clutch out bump started the engine.
 
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Re: Fixed my electrical problem (headlights, dash lites,horn, turn signals, windshiel

With the help of this community I quickly found the problem. The green wire (combined ground) on the 24 pin connector was burned. It appears that the actual pins in the connector overheated. The white plastic shell is a bit discolored. In my previous occupation as an Marine with an MOS of aircraft electronics technician the repair is straight forward---replace the connector. In my current occupation as a math and science teacher the repair is still very straight forward----solder in a jumper across the burnt pins of the 24 pin connector and ground it to the coil stud. Sort of like the other guy did, only I won't require a current path through the connector! I would include a picture but for some reason I can't up load it from my desk top. A big thanks to all:)
 
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dduelin

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Re: Fixed my electrical problem (headlights, dash lites,horn, turn signals, windshiel

Glad you got it worked out so quickly.
 
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60 miles from home yesterday the ground circuit problem happened again. The bike quit at a stop sign and from then on basically nothing electrical in the front half of the bike worked and the bike would not start with high beams on. The engine would start and run with the headlight dip switch on low beam although there were no headlights and I was able to ride it home. This problem is detailed in this earlier thread:

https://www.st-owners.com/forums/showthread.php?120747-Location-of-main-chassis-frame-ground-Ground-circuit-fault

When I got home I stripped off the tupperware and began reading all the threads again with similar problems. The ground wire out of the bottom of the 24 pin connector on the front left of the motorcycle above the cylinder head tested good continuity to the ground but because other similar problems with 1300s centered on this ground circuit I made a 14 gauge wire test lead with a pointed metal tip and inserted it into the plastic connector so it made contact with the connector's terminal for the green wire, bypassing the wire, and touched the other end to the frame while the key was on. All the lights came on brightly and the fuel pump spun up. Alright!!!!! To fashion a low resistance ground I cut the old ground wire in two and twisted and soldered a piece of the new wire onto it and crimped a ring terminal on the end. I grounded it to one of the 8 mm bolts that secure the left side coil.

Thanks to all of you that contributed in earlier threads I was able to get right to it and affect a repair.
Well you are correct on the fix. Did what you said and it all started working correctly. That you and everyone for their response
 
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This thread is timeless.
Good information to know and a ground connection that should be checked and cleaned before it leaves one stranded on the side of a road somewhere inconvenient at the worst possible time....... One can always add the extra ground wire before it becomes a problem.
 
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dduelin

dduelin

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This thread is timeless.
Good information to know and a ground connection that should be checked and cleaned before it leaves one stranded on the side of a road somewhere inconvenient at the worst possible time....... One can always add the extra ground wire before it becomes a problem.
As the ST1300 ages this issue will continue to increase. I think there are 4 posts in two weeks describing something weird happening with electrical devices in the front half of the bike. When it happened to my 2005 nearly 9 years ago Stan (V8-7) pointed me to a single ST-O post 1 or 2 years earlier that detailed this problem on a bike in the UK and how the owner crafted a new ground to a bolt fixing the left side coil to the frame.
 
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Yes! I remember this thread from years ago when I was adding aux lights to my bike. I checked and cleaned it at that time. Since I saw the other posts popping up, it reminds me to go check it again.....
 
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This thread is timeless.
Good information to know and a ground connection that should be checked and cleaned before it leaves one stranded on the side of a road somewhere inconvenient at the worst possible time....... One can always add the extra ground wire before it becomes a problem.
I wonder where the actual ground connection is for that green wire.
 
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dduelin

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I wonder where the actual ground connection is for that green wire.
It terminates where the front half of the wire harness bolts to the frame under the rear of the gas tank.
 

ST Gui

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I made a 14 gauge wire test lead with a pointed metal tip and inserted it into the plastic connector so it made contact with the connector's terminal for the green wire, bypassing the wire, and touched the other end to the frame while the key was on. All the lights came on brightly and the fuel pump spun up.
Not having seen the connector (yet)– in which side of the connector did you place the test lead? Although I guess it wouldn't be hard to figure out with a lead in hand. I'm also guessing it would be the 'front' side that doesn't lead or connect to the frame ground point if the connector were separated.
 

mjc506

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Yeah, front side of that connector. Providing an additional ground the the front subharness is not a bad idea :)
 
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