XJ650 Gauges on a XJ750 Seca

I deleted the Atari based on the writups a few have posted, and everything went great other than the tach. I tried to track down some wiring diagrams, and i'm fairly certain I hooked the tach up properly, but it doesn't read anything.

Anyone have any insight? Is there a way I can test the tach?

 

Nobody has any ideas? Maybe confirm my wiring is correct, or if there's some ohm reading to confirm the tach isn't burnt out, etc?

I have the diagrams for my XJ750, but i don't' particularly want to buy another FSM for the 650 just for the dang tach.

 

I just asked about something like this not long ago on a thread of mine for my 750, although only the engine is a 750, the rest is a 900, but I think MiGhost said that the XJ650 and XJ750 clusters would fit the XJ900. So these should be compatible, wiring looks similar. Maybe try hooking it up again, double check connections and what not. If there are connections you are unsure of, switch them around. If its not working, then in my mind its broken, so try whatever you can, best situation, you change the wiring and it works, worst case you kill it/kill it more. In 5 mins. of dicking around yo could have it figured out.

One thing to check if its dead and electronic, smell it. Yes, put it to your nose and take a wiff. When electrical stuff goes, if a part burns out, you will be able to smell it. If it smells burnt, it could be bad. If you can get it open and there is corrosion inside, its probably dead.

If doesn't seem like it should be dead, my approach would be wires with alligator clips, and connect it, check it, if it works, great, make note of connections, if not, change connections you are not absolutely 100% sure of, check and repeat until it works. Ones you would know for sure would be like ground (frame is ground). Don't assume the color code from the tach to the bike wiring is the same. When dealing with grounding wires (for any electronics) I have commonly seen green, brown, blue, yellow, or a striped combination of any of those 2 used for ground, so assuming a green wire is ground is not necessarily correct. The bike frame is/should be ground, so that one you shouldn't have to worry about, but unless you know a certain wire is from the coil, or this or that, you can't be 100% sure, and those are the ones that you change around.

Its surprising how well that approached can work. That is my 2 cents.

 

Yamaha generally uses black, no stripe, for ground.

 

Based on my wiring diagram for the XJ750 (the wires you're seeing in the pic, as labeled) I have identified which wire does what, it's where to hook them to on the gauge I wasn't 100% on and was hoping to get confirmed.

 

Trumpetrhapsody,

My bike and book show a orange wire where you have the grey meter unit wire. The orange wire is tapped into the 2-3 coil wiring from the igniter.

Gary

Edit: Looked at the schematics for the 750 J, K and MK. They show the grey wire going to the 2-3 coil. Hope this helps.

 

Thanks for the clarification, that's kinda what I thought. So it sounds like I have a dead tach?

 

The tach connection goes to the coil negative, not positive.