What kind of motorcycles exactly are both bikes?

 

The 1983 has a yellow wire from one of the ignition coils negative terminal. It is called the transistorized ignition system.

If the 1994 is a true CDI it has different signals to fire the coils. I don't have a manual to investigate the 1994.

 

Make sure you use a dedicated ground for the tach's ground wire. Don't tap into a ground wire. Connect the tach's ground directly to a frame bolt. PS: You also didn't tell us what brand of tach you have, so all I can go by is the tach I use, which is the Biker's Choice Custom Mini Tach.

 

I was recently looking at doing the same thing and wiring in a new tach. this guys video is what i watched hopefully it helps. Good luck

 

I thought I was pretty clear about what both bikes are. The donor is an '83 honda shadow vt750. The bike I'm looking to install the gauges on is a '94 Honda shadow vt1100. I've got them mounted. The lights work. Plus the speedometer cable. But I've tried tapping into both wires on the left coil with no success. I've always thought that there's got to be a signal to the negative terminal of the coils in order to saturate it. I have two shop manuals on the 1100 but the wiring diagrams don't show a tach on this model so it's a shot in the dark as to where the lead should come from. HELP!

 

In your manual, you will find that there are two different colored wires going to your Ignition Control Module from the coils. On the 2000 VT1100C, they are Blue/Yellow tracer and Yellow/Blue tracer. Can you find these wires in your manual?

 

I've got both shop manuals with the wiring diagrams open. The problem I see is that there is no dedicated ground from the tach I took off of my vt750. The only ground is for the lights. And that isn't a ground ground. If you know what I mean. I guess the proper term may be earth ground. It isn't connected to the frame. And that is showed in the 70 manual. So what do I do for a ground? I've reattached the yellow wire to the coils yellow with blue tracer but the tach won't work. I thought I was fairly knowledgeable about wiring and such but this is making me second guess my assessment. Any help will be appreciated. And thanks

 

1) How may wires, and what colors are the wires coming from your tach?


2) What wires coming from your tach are currently hooked up, and where are they hooked up to?

 

Is this diagram similar to yours? Open the thumbnail, then right click on it and then click on "View Image" to see it full screen.

 

Here is the back of the gauge on the 1983. The yellow wire into the tachometer itself, and a green ground going down the harness. Green is always ground.

 

Oh, for crying out loud. All this time I've been thinking he removed an aftermarket tach from one bike and was installing it on a different bike. Sorry for getting completely off track.... lol.

 

He is trying to swap from year to another but I don't know if the tach will work on a later ignition if it has gone to actual CDI.

 

Maybe they went to actual CDI in 1997 according to the Haynes manual. Then the coils are fired by a high voltage instead of a grounding signal as the older systems.

 

Can you tell by looking at the schematic? I posted up the schematic for the 1997-2007 earlier.

 

I forgot I was going to include this info from that Haynes manual. Shows 1997 as having the 100+ volt signal. I never have worked with this type system so I don't have any tips on diagnosis.

 

Thanks guys for all of the info but the wiring diagram for '97 isn't quite the same as for my '94. To make myself clear here I have taken the factory tach from my '83 shadow vt750 and have installed it on mt '94 shadow vy1100. Why, well because I'm anal about having all the info I can about how my machine is running. I appreciate the picture of the back of the tach. I didn't look at the back of mine. Just the wire loom coming from it. There was two green wires. One goes to the light. The other ties into it per the wiring diagram. This tells me that they're isn't a designated ground to the tach. The other green wire goes to the coolant team gauge. So I've left the tap into the coil where I should be getting a signal but still have to working gauge. I'm truely dumbfounded here as to my next step. Or maybe the term is just dumb! Thanks to all who responded.

 

Here's a list of the wires coming from the back of my vt750s tach. Br/B(2), Dg(2), Y, Br/W, G/L. Remember that this tach also incorporates a temp meter. I've tied the two greens together since they're both grounds. And according to the wiring diagrams aren't designated as being separate. Now as for the signal to the yellow wire, which should be the lead from the coil, the diagram on the 1100 shows only one wire that comes from the spark units that goes to the coils. This is the wire that I connected the yellow wire to. But no signal. So I'm really at a loss here. Thanks again for all the help guys.

 

Silly question - Did the tach work before???

You might test it by taking a long wire connected to the yellow tach wire and rapidly touching it to the positive battery post to see if an intermittant signal will register anything on the needle. Ground the green wire to the battery also.

 

The tach worked perfect before

 

Maybe there is battery power to the tach. I see a black/brown wire from a fuse that goes into the unit as the manual calls it.

 

Well I don't know exactly what I did or didn't do but the tach is now working as it should. PTL. I think it was one of the two green ground wires that I wired to the frame. That's all I can figure out anyway. I'd like to say thanks to all those who gave me such good advice no feedbak. It's appreciated.

 

Pics of it?

When I got mine, I initially wanted to put a tach on it, but after riding for a while I don't really feel a need for it.
Rev limiter keeps me from going to high, and I have gotten used to engine noise/speed/shift needs of the bike without a tach.

 

Good to hear it works.

 

I've taken the tach off of my '83 shadow 750 and want to put it on the '94 shadow 1100.

 

@reaper517, that's funny, there must be an echo in here, because that is where this thread started.

 

My old bike has a tach and I refer to it sometimes, but after riding it for a while you get used to the sound of the engine where you want to shift or run down the road.


Not sure the 1983's had a rev limiter but I would be afraid to find out as I see pistons flying out the sides.

 

I view rev limiters the same way I view ABS brakes on cars and trucks. If I rely on either, then I don't belong behind the wheel or the handlebars. With that said, the tach on my Honda is the best thing I added to it, and my only 'must have' mod.