msd rpm activated switch

[Nunook]

I need some help.I have the above listed part, and it needs a tach signal. When i hook it up the tach wire coming off the ECU the switch works but my tachometer doesn't. I figure the ecu can only supply enough power for one of them to work.

SO, where is another place I can hook this up too. I have a stock ignition system so no msd box to connect it too.

thanks in advance

[float_6969]

That's odd that the tach quit. Did you just splice into the tach wire? That shouldn't have made the tach quit. Regardless, I think the loop at the back of the coilpack subharness might work. I'm not real sure about that though...