how do ? about the tacho and the 3 clocks mini dasboard

SEB79 · Post by **SEB79** » Sun Dec 07, 2008 12:00 pm

hi

I wish to know how to do in order to use my tacho on the dashboard after megajolt instal.
thanks for help.

SEB79 · Post by **SEB79** » Mon Dec 08, 2008 10:36 am

could you try to use the white and black wire from the original coil to the rev out counter of the megajolt ?
idea ?

on the nippon 3 clocks, the tacho are two wire : one is the white and black wire (goes to negative coil) and one is orange and green (12 v).

tip and advice welcome

Post by **brentp** » Mon Dec 08, 2008 11:28 am

Hi,

Apologies for the late reply!

There are 3 basic ways to drive an OEM tachometer, in the order of preference: 1) using the TACH_OUT on the MJLJ; 2) using the diode circuit, sensing the flyback voltage from the coil packs; and 3) using the PIP line of the EDIS module.

See more information here:
http://www.autosportlabs.net/MJLJ_V4_ve ... achometers

SEB79 · Post by **SEB79** » Mon Dec 08, 2008 12:31 pm

i read this note but i wish to know how mini owners did in order to use their nippon tacho. On the mini forum, matt said he ran a fresh wire from the output on the Megajolt to the back of my dash, then ran another fresh +ve wire into the tacho with a 5A fuse inline IIRC.
If i use the white and black wire from the original coil and i fit this one to the out put on the megajolt and use the same orange and green wire . in my point of view, that the same thing that Matt explain.

I just want to know if mini owners did the same thing in order to use this tacho. Others use the pip...

well, i will be nejoy to read experience on this subject.

miniboo · Post by **miniboo** » Mon Dec 08, 2008 6:07 pm

try using the same wire as the standard install to the tach out and if it is bouncy then use the PIP signal. i used the PIP signal on my smiths gauge as the tach out from the MJ was bouncy and not reliable.

Post by **brentp** » Tue Dec 09, 2008 5:12 am

Note, the V4 controller improved the TACH_OUT compatibility by making it a mirror of the PIP signal, so I would recommend using this signal first.

SEB79 · Post by **SEB79** » Fri Dec 26, 2008 4:01 pm

I will finished all my wiring except the ground for TPS sensor and tach out wiring.

If I use the white and black wiring behind the tacho to the tach out of the mini (nipon tach) ! I'm asking aboout the other wiring green and orange... need to be connected to the 12V of the megajolt ?

What's more, the VR sensor is polarised. I chose to fit the white and red wiring for the sensor like being +, and brown and red for the ground... But none informations about Ford VR sensor....

If you have experiences about these points, glad to read your answers !

KLAS · Post by **KLAS** » Fri Dec 26, 2008 6:43 pm

the green/orange is power to the tacho, needs connecting to a switched 12V source as done by the factory. the tacho is grounded by the pcb foil at the back.
and as you already know the white/black gets the impulses from the coil or the MJLJ

SEB79 · Post by **SEB79** » Fri Dec 26, 2008 8:43 pm

tks

i didn't understand in firstwhat you want to mean by foil..the printed circuit board that is attached to the back of the speedo rev counter unit. ok mate

KLAS · Post by **KLAS** » Fri Dec 26, 2008 9:19 pm

if you use the Nippon Seiki 3 clock setup the 3 instruments are connected at the back with a pcb foil, just like the older Smith ones. you have just 2 connectors at the back of the tacho, one is 12volts (the spade, IIRC) and one is ignition puls (the round one). via the foil there is ground, it is connected with a screw, the one a bit higher and to the left of the 2 connectors (the other 2 just hold the instrument to the case). and the foil gives pover and ground to the small bulb at the upper end of the case