after market tachs

[ski3747270]

all I did when I installed mine was to run right into the existing tach wires.
No problem.

PM if you need

Chris

 

[Rusty McNeil]

someone must know , how to install a 5 inch autometer tach on the v-max ? Where to pull the tach reference signal from? I tried to wire it In 4 cyl mode and the reading on the tach was exactly half what it should be ( for example 55 mph usually is around 3000 or so well tach reads 1500 ?I wired it to the original tach wire !!!there must be a way:bang head:

The Vmax is has a "waste spark" firing system which means the coil fires on the exhaust stroke as well as the firing stroke.

The signal to the back of the factory tach is a very weak one, the only thing I ever got it to drive was my Raptor light, it would never drive my autometer.

If you need a "real" signal you can get it off the coil signal.

The commons on the coils are 12 volts positive which makes a little "dip" when the ground is supplied to the coil to fire it. Usually this will be enough to fire most tach drivers. If you use that you want to get it as close to the coil as possible as the "dip" will be greatest closest to the coil.

This is how I had to set up my autometer shift light/tach driver before I started using another method to drive it. I'm still using that same method to drive an rpm signal into my Wideband commander.

I'm pretty sure I had to set it 2 cylinder mode.

The other wire on the coil is a 12 volt negative signal which turns on and off completely as the coils fire.


Rusty

 

[Redbone]

Here is a pic of my gauges
Speedo
Tach
Fuel Pressure (NOS)
Oil Pressure
Volts
Water Temp
Manual Fan Sw

Very nice mod, the 3 guage tank cluster looks factory original!

 

[shawn kloker]

Here is a pic of my gauges
Speedo
Tach
Fuel Pressure (NOS)
Oil Pressure
Volts
Water Temp
Manual Fan Sw

What does rain do to that tach?

 

[lankeeyankee]

What does rain do to that tach?

Causes it to get wet:ummm:

 

[shawn kloker]

Causes it to get wet:ummm:

So none gets in and screws it up?