Tach Hookup Instructions from Nisonger

[Patrick67BJ8]

Okay, I received my rebuilt Tach with the instructions I've attached. I have a Pertronix Ignition, Negative Grd car. I'm not sure how to hookup the Tach after reading their instructions.
First Paragraph: Don't connect any of the wires that are part of the original loop.
Third Paragraph: Not sure what they really mean for me to do. The rebuilt Tach only has one white wire coming out of the back of it. The 1st paragraph says not to use any of the "loop" wires. Do they mean to cap the original Loop wire? If yes, then should I run a wire from the Neg terminal of the coil to the white wire that is coming out of the back of the Tach?

There's a total of 3 wires that are hooked up too the Tach, Black for grd, White from ignition for power and the White wire coming from the Neg terminal from the coil.
I spent almost $300 having the Tach rebuilt so I can't have any mistakes in hooking it up.
Thanks guys!

 

[rjc157]

I had the same problem with him he is just a condescending sob I could never get it to work all he would say is that I have a ground issue I made him put the old guts back in I'll check tomorrow how I got it to work

 

[dklawson]

OK... according to the instructions they sent you, you had Nisonger convert an RVI (current pulse sensing) tach to a later RVI type (voltage pulse sensing) tach.

The instructions say you have (1) white wire leaving the tach. On the tach you should find two spade lugs. One will be on an insulator, the other will be spot welded to the gauge case.

The original RVI tach wiring (before conversion) would have a loop of white wire on the back. Leave that wire connected to the existing wiring but NOT connected to the tach. Alternatively, you can just connect the car's original two white wires to each other and leave the white loop wire out completely. That group of wires carry current from the ignition switch to coil (+).

Run a wire (preferably green) from the insulated terminal on the gauge case to a switched terminal on the fuse box. (Basically... connect the insulated spade lug to any of the green wire circuits in your car).

Run a second wire (preferably black) from the spade terminal spot welded to the gauge case to a ground/earth connection on the car's chassis.

Lastly, extend the converted tach's white wire so that you can connect it to the coil's (-) terminal (the terminal with the white/black wire going to the distributor). Ideally the wire from the tach to the coil (-) terminal will also be white/black.

That's all there is to connecting the tach except for adding a lamp connection. Green and black wires are readily available locally. If you are lucky you can also get white/black wire locally. If not, it is available from Britishwiring.com

 

[Patrick67BJ8]

OK... according to the instructions they sent you, you had Nisonger convert an RVI (current pulse sensing) tach to a later RVI type (voltage pulse sensing) tach.

The instructions say you have (1) white wire leaving the tach. On the tach you should find two spade lugs. One will be on an insulator, the other will be spot welded to the gauge case.

The original RVI tach wiring (before conversion) would have a loop of white wire on the back. Leave that wire connected to the existing wiring but NOT connected to the tach. Alternatively, you can just connect the car's original two white wires to each other and leave the white loop wire out completely. That group of wires carry current from the ignition switch to coil (+).

Run a wire (preferably green) from the insulated terminal on the gauge case to a switched terminal on the fuse box. (Basically... connect the insulated spade lug to any of the green wire circuits in your car).

Run a second wire (preferably black) from the spade terminal spot welded to the gauge case to a ground/earth connection on the car's chassis.

Lastly, extend the converted tach's white wire so that you can connect it to the coil's (-) terminal (the terminal with the white/black wire going to the distributor). Ideally the wire from the tach to the coil (-) terminal will also be white/black.

That's all there is to connecting the tach except for adding a lamp connection. Green and black wires are readily available locally. If you are lucky you can also get white/black wire locally. If not, it is available from Britishwiring.com

ill take a photo of my old Tach wiring/hookup and my new Tach and post tomorrow. There's only one spade, I believe, on the back of the Tach now and a green wire was hooked up to it.

 

[dklawson]

A picture is worth a thousand words. I'll make an effort to check back tomorrow.

 

[Patrick67BJ8]

Here is photos of the back of my Tach, with wires connected, and the back of the Tach rebuilt with notes in black where things go.

 

[bdcvg]

I just did this Myself, don't over think it. Run a wire from the tach to the Neg. post on the coil. That's signal in. 2 connect the green wire to the + 12v , that's the fused power. If You trace that green wire it goes to the fuse box. 3 attach ground to a mounting stud. 4 insert light bulb.

 

[Patrick67BJ8]

I just did this Myself, don't over think it. Run a wire from the tach to the Neg. post on the coil. That's signal in. 2 connect the green wire to the + 12v , that's the fused power. If You trace that green wire it goes to the fuse box. 3 attach ground to a mounting stud. 4 insert light bulb.

"Run a wire from the tach to the Neg post on the coil" , do you mean a new wire and it'll be connected with the white wire that's already on the vCoil post?

 

[bdcvg]

Yes that's how I did it. don't use the old white wire that had the loop in it at all.

 

[Patrick67BJ8]

Yes that's how I did it. don't use the old white wire that had the loop in it at all.

Thanks, that's how I thought it was to be done but always good to double check.

 

[bdcvg]

I stared at My car for 3 hours trying to figure out what They meant and realized I was just trying too hard. Hence the "don"t over think it"

 

[Keoke]

A picture is worth a thousand words. I'll make an effort to check back tomorrow.

Yeah DK, but your words were spot on.

 

[dklawson]

As above.

However, regarding the loop wire.... If you remove it completely, you will have two white wires that used to connect to the loop. Connect those two white wires to each other. As I mentioned in my last post, that is power to the coil.

 

[Patrick67BJ8]

As above.

However, regarding the loop wire.... If you remove it completely, you will have two white wires that used to connect to the loop. Connect those two white wires to each other. As I mentioned in my last post, that is power to the coil.

that makes sense. I was starting to think that they should be left alone but I can't find my wiring diagram that I had enlarged and mounted to a piece of gator board to double check myself.

 

[Patrick67BJ8]

Yeah DK, but your words were spot on.

Guys are visual, we need a picture painted.

 

[Keoke]

"Guys are visual, we need a picture painted."

Why!!atrick

Seem like all you do is lose em.-----

 

[Patrick67BJ8]

"Guys are visual, we need a picture painted."

Why!!atrick

Seem like all you do is lose em.-----

iIf you saw my garage right now you'd understand.

 

[Keoke]

iIf you saw my garage right now you'd understand.

OH man can't they get messed up ?.
I need a map to get around in minelayful:

 

[bdcvg]

You don't remove the loop wire, You leave it alone and out of the way.

 

[Patrick67BJ8]

You don't remove the loop wire, You leave it alone and out of the way.

I got the Tach all hooked up and fired up the engine, Tach shows 1000 RPM but when I rev the engine it drops off to zero. I double checked all connections and they appear to be good. The Tach before I had it rebuilt would go to about 2700 rpm before it dropped off to zero but the longer I drove the car the Tach would actually increase in RPM's shown on it. Peter at Nisonger said that it may have worked good when I first installed the Pertronix but it got worse the more I drove the car. The Tach worked great before I did the frame-up restoration. Photos of the coil connections. There's 3 wires on the Neg side of the coil, the old original white wire, the new white wire that I just ran to the white wire coming out of the Tach and the Red wire for the Pertronix.