MK1 lotus escort Aftermarket tacho HELP

Hello all,
I have bought a SAAS aftermarket tacho, is it possible to connect the tacho trigger wire without having to pull the original dash cluster out?
If not what wire do I connect too, for the aftermarket tacho to work.
Thanks
I have bought a SAAS aftermarket tacho, is it possible to connect the tacho trigger wire without having to pull the original dash cluster out?
If not what wire do I connect too, for the aftermarket tacho to work.
Thanks