78 GS750E "No Spark"

[Guest]

It’s near the back of this factory service manual found on BikeCliffs website. Use that for reference. Nessism made a nice diagram to show this. I’ll try to find it but here’s the jist of it. All 3 wires from the stator go to the 3 black wires from the left side of the SH775/ Triumph connector. Left side has 3 wires. It doesn’t matter which stator wire to which RR left side wire. They’re all the same. This will leave out a W/G wire and a W/R wire that go to the headlamp bucket, make a loop and come back. Tape those up and tuck them away. They’re no longer needed (never were?)

Right side of the RR/triumph connector has 2 wires. Black one goes to ground (solenoid mount bolt is a good place for that and other grounds, then one hefty ground wire to Battery -. Opinions differ on the validity is a single point ground(SPG). I use one. The reddish brown wire from the RR/Triumph connector goes to the red wire that was originally connected to your original Rectifier. It should have a fuse in its line. Don’t cut that off.

Those are the best instructions I can come up with. I am by no means an expert. I did this exactly 1 time. Posplayr, Steve, Nessism are the guys to follow. Hopefully one of them will chime in if I’ve gotten something wrong

Here’s Nessism’s diagram
SH775 Install by nessism, on Flickr

Thanks Rich!!!

 

[allojohn]

Hey Rich,

The wire connector came today so if you would be kind enough to direct me to a wiring diagram for a 1978 GS750 I'd appreciate it!

Thank you!
Shred

Someone posted a really nice color diagram for the 8V 750 among others, I can't find the post. I downloaded the diagram - it's so much clearer than the B/W factory effort. Maybe someone else remembers where it came from....

 

[Guest]

Thanks Rich!!!

Hey Rich,

Here is what I'm looking at

https://kenmurray.smugmug.com/1978-Suzuki-GS750/i-z9FN7sR/A

https://kenmurray.smugmug.com/1978-Suzuki-GS750/i-JtVwb8r/A

The side cover fits fine. In the second image the center yellow wire is coming from the old voltage regulator. I know that it is now redundant and not needed. I know the three yellows from the stator go to the light gray connector and I'll cut and splice those with electrical splicers. Do you see in the first image the three ground wires going to the negative terminal on the battery???? The thick black wire comes from the solenoid and the other two white and black striped ones (2) I have no idea.

 

[Rich82GS750TZ]

The black wires with the white stripes are all ground wires from the harness. I THINK (not an expert) it’s ok to have them all on the - battery terminal. But for me, I like to have only one lug on each battery terminal, except for the lugs for my battery tender plug. Technically, the battery tender negative lug could go on the SPG or other frame mounted bolt, but I like them on the battery and think it's OK. I have all the ground wires including the black from the right side of the RR (bottom one in your second pic) and a thicker black wire that goes to the engine case all mounted to a single point ground (SPG) that is one of the solenoid mounting screws. Then one thick Black wire from the SPG to the -battery terminal.

SPG

Engine Ground Wire. I BELIEVE (again, not an expert) that all GSs have a ground bolt in this general location.

 

[Guest]

Thanks Rich!!!

Hey Rich,

Here is the update. The left red wire going left from the (yellow) splice goes to the main harness. The center red wire goes up to the battery. I have a third red wire coming from the back harness that I don't know where to connect it.

https://kenmurray.smugmug.com/1978-Suzuki-GS750/i-Kp5LC54/A

Thank you,

Shred

 

[Rich82GS750TZ]

I’m attaching what I believe is a good representation of tour bikes wiring diagram, with the separate Regulator and rectifier from the manual. The red wire originally connected to your Rectifier should connect to the Red wire coming from Your new SH775, keeping the in-line fuse. I really don’t know about the others. I’m stumped.

There’s some stuff in your pick I don’t understand. That yellow splice, and the black connector that the red wire from the yellow splice feeds.

 

[Guest]

I’m attaching what I believe is a good representation of tour bikes wiring diagram, with the separate Regulator and rectifier from the manual. The red wire originally connected to your Rectifier should connect to the Red wire coming from Your new SH775, keeping the in-line fuse. I really don’t know about the others. I’m stumped.

There’s some stuff in your pick I don’t understand. That yellow splice, and the black connector that the red wire from the yellow splice feeds.

No worries, it's simple. The black connector is the original end to the trimph connector you told me to cut off. The red wire with the fuse was never connected to the original R/R now it's part of the splice that includes the red to the main harness and the redish brown wire from the 775. It was a stand alone directly to the battery before. The red one on the far right was originally connected to the stator.

It doesn't mean the original owner had it right.

 

[Rich82GS750TZ]

No I guess the OP definitely did not have it right if he had a red attached to the Stator. Unfortunately I can not in good conscience attempt to guide you further. This is as far as my limited knowledge can get you. You’ll have to get other help to help you undo and make right what the OP did. Use the wiring diagram.

Anyone else following along and able or willing to throw your 2 cents in, please do.

 

[Guest]

No I guess the OP definitely did not have it right if he had a red attached to the Stator. Unfortunately I can not in good conscience attempt to guide you further. This is as far as my limited knowledge can get you. You’ll have to get other help to help you undo and make right what the OP did. Use the wiring diagram.

Anyone else following along and able or willing to throw your 2 cents in, please do.

No worries Rich! It's all good brother!!! I'll get this.

Thank you for you bringing me this far!!

Shred

 

[Rich82GS750TZ]

I do see a mistake on the wiring diagram. I’m sure this happens. First one I’ve found. The wire marked Y/G coming out or the fuse that’s on the red wire coming from the Regulator. That Y/G should be on the wire to it’s left that is the signal wire to the solenoid. The mismarked wire should be R (red)

 

[Guest]

I do see a mistake on the wiring diagram. I’m sure this happens. First one I’ve found. The wire marked Y/G coming out or the fuse that’s on the red wire coming from the Regulator. That Y/G should be on the wire to it’s left that is the signal wire to the solenoid. The mismarked wire should be R (red)

I made a mistake. The red wire on the far right went to the original rectifier. What is the fuse protecting? The battery or the harness.

 

[Rich82GS750TZ]

It’s regulated / rectified current coming from the RR on its way to charge the battery, so I would assume it’s to protect the battery.

 

[allojohn]

Found it....

 

[Guest]

Thanks you guys!!! It looks like I can kill the right red wire and go red stand alone R/R to the battery with an inline fuse.

 

[Guest]

If you're reading this thread there is good information here but find a better thread to read on the subject as I was never able to do this upgrade and went back to the original stock system. Maybe someone could provide a link to a better thread.