1982 GS750T - R/R Connector Help Required...

[pdqford]

My bad! I just found the wiring diagram for the T, so I'm going to modify my previous post.
I surly didn't mean to make this even more complicated by trying to revise my previous post, but here goes.

Okay Sam, thanks for that video.

One thing I am not sure about is why your white 6-pin R/R connector wires are different from the picture Rich posted of his white 6-pin R/R connector wires. Don't you both have T's?

Based on this pin-out of a 6 pin connector:

https://images.app.goo.gl/v3kPe4sGrhKHYp3n6

it appears to me that the typical pin layout of a 6-pin R/R puts the three stator wires together, while the other three pins represent the R/R power out pin, the R/R ground pin, and the R/R sensing pin. So the yellows from the stator go to the lower three pins of the R/R.

That leaves us with those upper three pins on the R/R. And the B/Y looks to be the ground.

I suspect the two red wires represent the power wire out and the sensing wire.

So here is how I believe the the other red wires (three of them!) function.

The smaller red wire that connects to your battery + post and goes into the main harness carries power to the fourth fuse down (labeled MAIN) in your fuse block.
(I don't know why it is a 10A fuse as it originally was a 15A fuse.) That MAIN fuse feeds power thru a red wire that goes up to the ignition switch. When the ignition switch is turned on, an Orange wire brings power back to the fuse block and powers the top 3 fuses (which were originally 10A fuses).

I assume the R/B wire that you show going from the fuse box to the center pin on your white connector and then into the center pin of the R/R is powered by the MAIN fuse so that the R/R can monitor system voltage. (I'm not sure that it is a good idea for the R/R sensing wire to be powered all the time - even with the bike off).

To prove this out, break out your ohm meter and put one probe on the R/B wire (your WIRE TWO) going from the fuse block to the center pin of the white connector and the other probe on the red wire that connects to the battery + post.. I would expect continuity, ergo: the R/R sense the system voltage! (all the time?)

The final red wire (the one you referred to as WIRE ONE) that goes from the upper left pin of the connector into the main harness is the R/R power out wire from the R/R. Within the main harness that power out wire is spliced into the red wire that goes from the MAIN fuse to the ignition switch (described above). That allows the R/R to supply power to the ignition switch (and the vehicle electrical load) and/or a convoluted path back to the battery + post to charge the battery.

To prove this out, break out your ohm meter. Connect one probe to the smaller red wire that connects to the battery + post and the other probe to the power out wire from your white connector. Should always show continuity.

So that's how I figure the PO had the bike wired. No guarantees !
Hopefully it will make it easier for you to go from the current wiring to the one that Nessium reccomends.

And I hope someone will come along and check to see if I maybe I made some wrong assumptions.

[SamLack99]

To prove this out, break out your ohm meter and put one probe on the R/B wire (your WIRE TWO) going from the fuse block to the center pin of the white connector and the other probe on the red wire that connects to the battery + post.. I would expect continuity, ergo: the R/R sense the system voltage! (all the time?)

With the ignition switch off = No continuity
With the ignition switch on = Continuity

The final red wire (the one you referred to as WIRE ONE) that goes from the upper left pin of the connector into the main harness is the R/R power out wire from the R/R. Within the main harness that power out wire is spliced into the red wire that goes from the MAIN fuse to the ignition switch (described above). That allows the R/R to supply power to the ignition switch (and the vehicle electrical load) and/or a convoluted path back to the battery + post to charge the battery.

To prove this out, break out your ohm meter. Connect one probe to the smaller red wire that connects to the battery + post and the other probe to the power out wire from your white connector. Should always show continuity.

With the ignition switch off = Continuity
With the ignition switch on = Continuity

Thank you, Jim =)

What I'm concluding from this is:

Red wire (one) will go into the R/R
Red/Black wire (two) is going to be removed.

So...

...The wires for the two connectors that go into the replacement SH775 R/R.

Connector 1 (Grey) will get the three yellow wires from the stator
Connector 2 (Black) will get the black/yellow wire (four) and Red wire (one)

Now then, do I need to put a 30amp fuse inline on the Red wire (one)?

And if yes, can anyone recommend a simple way to put a 30amp fuse inline on Red Wire (one)?

Thank you =)

[dgates1]

That should be fused through your main fuse on the block. But like pdqford mentioned, usually larger than 10amp.

Could test by doing continuity on that line again and take out the fuse to see if that breaks it.

[pdqford]

Now then, do I need to put a 30amp fuse inline on the Red wire (one)?
;

Well, the factory didn't use an extra fuse in that red wire. It goes up into the harness and is spliced into the red wire that runs from fuse MAIN to the ignition switch.
So power out from the R/R can go two ways. The power can go from the splice up to the ignition switch, and with the ignition switch on the power will come back down the orange wire and feed the top three fuses in the fuse box. And/or the power can go from the splice back to the fuse box, back thru the MAIN fuse and on to the battery.

You can probably remove the fuse box and pop the back off to see what wires go to which fuse, just in case the PO changed anything.

If you decide to add an in-line fuse, 30A is way too big. A short would probably melt some wires before the fuse blows. Again, the factory used a 15A fuse in the MAIN fuse. I don't know but I suspect the charging system would struggle to put out 15A.

Hopefully one of the electrical guys like Nessism or David will come by and verify.

[SamLack99]

Ah, I see.

I hadn't understood that the power went through the fuse box (eventually).

So a 15Amp fuse in the Main slot 'should' take care of it.

Got some time off work coming up soon, and I'm looking forward to investing it in putting Suzy back together and seeing if she'll start.

I'll keep you posted =)

Thanks again everyone!

[Rich82GS750TZ]

Point of clarification. My pics of a six (actually 8) pin connector are what is connected to the bottom of the fuse box and in no way should they be confused with what Sam had going into his SH555-12 RR. My confusion still lies in Sams pics seem to show no wires in this connector where mine show 2 reds.

[SamLack99]

Good point Rich,

Tomorrow, I'll get a picture of the wires going into the connector that goes into my fuse box.

I'd do it now, but it's way past my bedtime =)

[pdqford]

Just an FYI, on BikeCliff's website, page 66 of the GS750ET service manual has the wiring diagram for the GS750T(Z).

[Rich82GS750TZ]

Here it is…………….

[SamLack99]

Here's a video of the wires going into the connector that connects to my fuse box...

I just noticed, I have two cables going into the orange/green slot. Huh?

[Rich82GS750TZ]

Everything there looks same as mine, but your 2 empty slots on the right where I have 2 reds. If I get a chance tomorrow, I will trace them to where they go to/come from exactly, If I can do it without tearing everything apart. My Tiger is down at the moment, and the weather is just too nice to be without a bike.

[pdqford]

Since your wiring has been modified by the PO, you don't necessarily need a red wire going to the fuse box.

The PO may have taken that 2nd red wire from your battery positive post, that went to a bullet connector down near the electrical panel, unplugged it, and connected it to the red wire that goes up to the ignition switch (since the + side of the ignition switch is hot all the time, even from the factory).

When the ignition switch is turned on, power comes back down the orange wire to power up the top three fuses of the fuse block. Where that orange wire enters the fuse box is where the PO picked up the sensing voltage for the old regulator. That way the sensing wire going into the old regulator is only powered up when the ignition key is on.

Since this is only a guess, so to verify, where does that 2nd wire from your battery + post end up?

[SamLack99]

Since your wiring has been modified by the PO, you don't necessarily need a red wire going to the fuse box.

The PO may have taken that 2nd red wire from your battery positive post, that went to a bullet connector down near the electrical panel, unplugged it, and connected it to the red wire that goes up to the ignition switch (since the + side of the ignition switch is hot all the time, even from the factory).

When the ignition switch is turned on, power comes back down the orange wire to power up the top three fuses of the fuse block. Where that orange wire enters the fuse box is where the PO picked up the sensing voltage for the old regulator. That way the sensing wire going into the old regulator is only powered up when the ignition key is on.

Since this is only a guess, so to verify, where does that 2nd wire from your battery + post end up?

Hey Jim,

I'll see if I can find out tomorrow. Should be fun =)

[salty_monk]

The 555 is a Mosfet but not a series RR. Like a lower power version of the FH012 that everyone moved to before we learnt about the SH775 I think. The Elektrex you see in the Post is long out of business. They were a US company that made parts for Harley's it just so happened that they had one RR that worked well for the GS.

What you see in the UK is either just coincidence or someone trying to take advantage of the name....

[GSXR7ED]

Sub'd for future reference.