Reserve Lighting Device / Head Light Fuse

[3Phase]

I dunno, Rob, adding an extra ground for the horn and starter buttons makes sense; forgetting about the existing pinout doesn't though, really.


Regards,

Scott

[79XS11F]

I dunno, Rob, adding an extra ground for the horn and starter buttons makes sense; forgetting about the existing pinout doesn't though, really.


Regards,

Scott

I'm not even sure if the switches are grounded to the handlebar or not I have not looked at the wiring diagram since sorting this issue out. If the switch body's are grounded to the handlebars the only real need for a ground wire would be if the handle bars were rubber mounted. There is no ground wire in the harness side of that connection block and the original switch dose not have this ground wire in its lead. I will look closely at the diagrams for other models and see if / when that wire appears.
Rob

[3Phase]

I'm not even sure if the switches are grounded to the handlebar or not I have not looked at the wiring diagram since sorting this issue out. If the switch body's are grounded to the handlebars the only real need for a ground wire would be if the handle bars were rubber mounted. There is no ground wire in the harness side of that connection block and the original switch dose not have this ground wire in its lead. I will look closely at the diagrams for other models and see if / when that wire appears.
Rob

<laughing> I did that day before yesterday when I was tracing the headlight circuit to ensure that I wasn't sending you off on a wild goose chase. I don't know what's inside your 2H7 switch. You'd have to tear it down and look but that'd be a complete pain and totally unnecessary now that your lights are working -- leave it the [....] alone.

The schematics show the start and horn buttons as the only things that ground to the handlebar. I've seen a few suggestions here and there about running a braided metal strap from the triple tree or somewhere thereabouts to the frame for a better ground; supposed to make the starter start and help the horn honk.


Regards,

Scott

[79XS11F]

In my manual the wiring diagram for the 78 and 79 standard models does not show any of the handlebar switches going to ground by way of wiring or the handlebars themselves. They all have independent wiring and none are black. However, the wiring diagram for the 1979 special model does show a BLACK wire with in the right hand side switch lead. On later models each switch of the handlebar set is shown in detail but in no case do any go to ground through the handlebars. I will conclude that this switch is actually from a special model.
Rob

[3Phase]

Is there more to the 2H7 part number?

In my manual the wiring diagram for the 78 and 79 standard models does not show any of the handlebar switches going to ground by way of wiring or the handlebars themselves. They all have independent wiring and none are black. However, the wiring diagram for the 1979 special model does show a BLACK wire with in the right hand side switch lead. On later models each switch of the handlebar set is shown in detail but in no case do any go to ground through the handlebars. I will conclude that this switch is actually from a special model.
Rob

Guru Rob, you are correct and I missed the black wire on the Specials, I was looking at the wires for the Headlight switch -- no excuse!

Little things like the Headlight switch and some other errors, omissions and additions that may or may not be present on a given model are the reason I stripped out my '80G wiring harness and tore down every switch and electrical accessory to make my own schematic.

Your part has a 2H7 prefix so I did some digging on the Yamaha site.

Naturally, the '78E does not use a 2H7 part number, it uses a 1T5 number and Yamaha can't make up its own mind about how to number its handlebar switches.

There are two 2H7 part numbers for '79F/80F Standard models.

The '81H Standard appears to have its own 2H7 part number. It could be a typo' or it could be a genuine change. I don't have a schematic for that year/model so I can't check it.

There is only one part number for all of the Special models and it begins with the '79SF 3H3 prefix. That part should have the Black wire.

The '82XJ has its own 10M part number.

78E	1T5-83963-00-98	SWITCH, HANDLE 3 RIGHT	LOW GLOSS BLACK
	(1T5 is a 1977 XS750D model prefix)

79F	2H7-83975-01-00	SWITCH, HANDLE 2 RIGHT	LOW GLOSS BLK
79SF	3H3-83975-00-98	SWITCH, HANDLE 3 RIGHT	LOW GLOSS BLK

80G	2H7-83975-01-00	SWITCH, HANDLE 2 (2H7-83975-00-98)LOW GLOSS BLK
80LG	3H3-83975-00-98	SWITCH, HANDLE 3 (R.H.)	LOW GLOSS BLK
80SG	3H3-83975-00-98	SWITCH, HANDLE 3 (R.H.)	LOW GLOSS BLK

81H	2H7-83975-00-01	SWITCH, HANDLE 2 (2H7-83975-98)
81LH	3H3-83975-00-98	SWITCH, HANDLE 3 (R.H.)	LOW GLOSS BLK
81SH	3H3-83975-00-98	SWITCH, HANDLE 3 (R.H.)	LOW GLOSS BLK

82XJ	10M-83963-00-00	SWITCH, HANDLE 3

So, until I can physically look at the different "Switch, Handlebar" parts in my hand there are at least three possibilities:

The '81H 2H7-83975-00-01 part number is a typo' or a purely cosmetic change.

The '81H 2H7-83975-00-01 part has a Black wire and different different pinout.

The original, obsolete, 2H7-83975-00-98 part number for the '79F/'80G has no Black wire and the original pinout but the new replacement 2H7-83975-01-00 part has a Black wire and a new pinout.


Regards,

Scott

[79XS11F]

I'm just glad I found it fast and didn't start tearing into my new wiring harness looking for a problem that did not exist within the harness.
Rob

[3Phase]

I'm just glad I found it fast and didn't start tearing into my new wiring harness looking for a problem that did not exist within the harness.
Rob

Oh, yeah, I've done that a few times; got pretty good at repairing and making new wiring harnesses, too.... <whistling innocently>


Regards,

Scott

[petejw]

hey Rob,
Glad you found the problem, nothing harder than trying to track an electrical problem.

Im looking at a right hand switch of a 81 special
dnt know if theyre the same or not, but this switch
has a black ground wire attached below the light switch,
and looks like the plate holding the wires in, earths to the handle bars, also the alloy body of the switch would also earth out. That black wire goes to a 4 prong connector with 2 red/white wires and a blue/white lead.

[3Phase]

That black wire goes to a 4 prong connector with 2 red/white wires and a blue/white lead.

Pete, is there a part number on it anywhere? It's from a Special so it should be a 3H3 part.


Regards,

Scott

[petejw]

Scott,
I cant find a part number on it,
sorry I wrote its a special in the previous post,
but im in aus, these bikes are similar to a special
but not exactly the same, my frame/engine id begins with 5N5.

[3Phase]

Scott,
I cant find a part number on it,
sorry I wrote its a special in the previous post,
but im in aus, these bikes are similar to a special
but not exactly the same, my frame/engine id begins with 5N5.

Oh, right, sorry! Okay, so no part number for Aussie Specials. It's a conspiracy!


Regards,

Scott