Tacho wiring

[48pop]

Hi Folks,

managed to get a hold of a GT Tach, (I think). Can anyone help me with wiring it into my 122s??

Confusingly it has 2 white wires, one black and 2 red...One of the red ones is for illumination...Any idea what I should do with the others?

I don't even know if it works yet....

Cheers
Gerry

[loon]

Originally Posted by 48pop

Hi Folks,

managed to get a hold of a GT Tach, (I think). Can anyone help me with wiring it into my 122s??

Confusingly it has 2 white wires, one black and 2 red...One of the red ones is for illumination...Any idea what I should do with the others?

I don't even know if it works yet....

Cheers
Gerry

sell it to me for a £5

but seriously i think the white ones are low tention in and out
conect one to the coil lt and the other to the distributor
red power and black earth

[48pop]

Just found this......
http://hem.bredband.net/b215872/amaz...o%20Amazon.pdf

I am missing a small part of the mount.....The finisher around the base if anyone has one....

Cheers
gerry

[archieboy69]

Is it part number 18 on the pic your after?

Thats a good find, so i have an original GT one by the sounds of it, cool!

Stu

[48pop]

Its the bit directly above No 18....

[archieboy69]

Thats a shame, got all other bits, i have got a different style of foot, its a round one, donno if its any good to you?

[48pop]

Sure I could probably rework the mount.... Let me see if if it works first !

[Mike Arnold]

I fitted a Smiths taco to my 122S but I am not familiar with the exact type used on a 123GT. The one I have has ground, 12v and illumination. The low tension wire to the coil (ie the one between the coil and the points) is looped through the pickup clamp on the back of the unit. The taco picks up the current pulses that flow through the wire in what is, in effect, a transformer. On this type you do not make a bare wire connection between the coil and the unit. Magic, eh!

Incidentally, without custom electronics, you cannot use this type of taco with most electronic ignitions.

Finally, this is bad news for radios because the wire from the coil transmits awful noises once inside the cabin.

[222s]

Originally Posted by Mike Arnold

Incidentally, without custom electronics, you cannot use this type of taco with most electronic ignitions.

I'm guessing that it stalls the engine?

*remembers antics at Wheels Day when Archieboy & I tried to test one of these tachos on my electronic ignitioned Amazon....*

[Mike Arnold]

I assume that you are commenting on using the tacho with electronic ignition. It is unlikely to cause any problems to the running of the engine but the current pulse that the tacho detects is different when electronic ignition is fitted and this can cause the tacho to misread.