How to test Tach...

[mjtoll23]

Hello,

I am having problems getting my tach to work on my 88 turbo with a 1J swap. It has not been working since I bought it and I have not been able to figure it out. There is continuity between the ignitor and the tach plug in. I also tried jumping the wire from the ign check box to the tach and still nothing. Im thinking my tach my be broken. Does anyone know how to test it? Or how I can make sure there is a signal being sent to the tach plug in? Im not the best with wiring.

Thanks,

Mike

 

[jetjock]

It's a moving coil type ammeter tach and can be easily tested depending on a few things. Do you have the cluster in or out of the car? If out is the tach in or out of the cluster?

 

[mjtoll23]

The cluster is currently out of the car, but the tach is still in the cluster.

It's a moving coil type ammeter tach and can be easily tested depending on a few things. Do you have the cluster in or out of the car? If out is the tach in or out of the cluster?

 

[jetjock]

Look at the back of the cluster where the tach mounts. From top to bottom you'll see three screws labeled:

1) IGN -

2) Earth

3) IGN +

Connect + 12 volts to IGN +

Connect ground (battery negative or body ground) to Earth.

Take a jumper from IGN + and several times touch or "rub" IGN - with it while watching the tach.

All this will prove is the tach works. It doesn't mean it'll be accurate with the 1J, etc. I'm assuming your statement "I'm having problems getting it to work" means no indication at all.

Be careful. I'm not responsible for you blowing something up. If I were you I'd put a 1 amp fuse in the +12 volt wire.

 

[mjtoll23]

Thanks for the help and information. I tested the tach by jumping the ign - and + and still nothing worked. So, I bought another proven tach and I have the same problem. There is a consistent tach voltage signal at the igniter, diagnostic box, and the back of the cluster. But, it only reads at fractions of 1 volt.

What is the tach output signal supposed to read for a 1jz?