1976 wiring - UNused plug and odd gizmo

[MaxPete]

Dear All:
I am restoring a '76 C-model and trying to repair the goofy wiring done by the P/O (he actually used house wiring components including Marettes and solid wire). I finally gave up and have bought a new harness from Mike's XS, but I have found an odd thing in changing from the old harness.

On the OLD harness there is a little device under the tank - near the coil / condenser / points wiring rats-nest - but it isn't referenced on any of the wiring diagrams as far as I can tell. The gizmo is a little black cylinder about 1.5" long x 1/2" dia. and it is connected to a black wire and a white wire with a black stripe.

Anybody know what that thing is? It does NOT look like a P/O modification - it was put there by Yamaha, I'm pretty sure.

Now, on the NEW harness, there are two connectors in the same location - but they are on Blue-Red and Blue-White wires..... Do I need to move the little gizmo over to the new harness - and what the heck is it?

Pictures are attached and any suggestions would be welcomed!

Many thanks,

Pete

 

[5twins]

I think that's a diode wired into the rear brake shoe wear warning circuit. Go to the tech section and to the "some Wiring Diagrams" thread. There is a '75-'76 diagram there that shows it. Although the wires on the diode a black and white/black, it appears they connect to the blue/white and blue/red.

 

[MaxPete]

Thanks so much 5Twins - I guess I will swap the gizmo over to the new harness and see what happens!

Cheers,

Pete

 

[MaxPete]

OK - now I've found something else interesting....this time in the headlight bucket mess-o-wires.

There are 3 or 4 Blue wire which are for always on lighting functions such as taillights, instrument lights etc. The Mike's XS main wiring harness does not have a connector for these Blue wires. The old harness did have one - it could receive three male bullet connectors - but the new harness has no female connector - only a single male Blue one.

So....I fabricated a little pigtail with a bunch of female connectors and plugged it onto the main harness and then connected the others. Anyhow, the point is that the new harness definitely seems to have an error built into it.

Unfortunately, it appears that in my previous experiments with the P/O messed up harness, I used up all of my main (20A) fuses so I'll have to wait till tomorrow to see if anything works. Oh well, I think I'll sit and enjoy a BEvERage and relax.

Cheers and thanks for the help earlier 5Twins!

Pete

 

[lakeview]

What a coincidence! I am swapping a new wire harness in to my 76 and had the same two questions, came to the same fix with the pigtail I cut off the old harness to collect all those loose blue ends (3) and the diode thing up near the coil hookups, so I will plug it into the blue white and blue red leads and see what smokes!
Next I am heading farther back in the harness and I am sure more head scratching because the po installed a PMA, solid state regulator & rectifier, but used a battery instead of a cap for which I am glad. A cursory look makes me think that the harness may be plug and play. Stranger things have happened in a world where a po thinks a spade terminal is a good substitute for bullet/socket connection.
Great day for working outside in the Golden Horseshoe.

 

[MaxPete]

Indeed! I went for a nice sunny-day ride on the back roads of Essex County down to Erieau for some wings and BEvERages. Super day for almost anything - except snow shovelling!