Tach Help

[Bajabrewer]

So I was digging thru a box & came across this tach that was originally on my 74 Bronco. The 74 was a 200 - 6 and the tach was on it when I bought it. As I was selling the Bronco I grabbed the tach and dropped it in a box figuring I would use it someday. Well I'm hoping that someday is now as I have a 66 with a 170 - 6 in it. I don't remember if the 74 had points or dura-spark & I don't know if the tach wiring went to some kind of connecting box or what it was 34 years ago. The 66 has an HEI distributor & has a tach output on it. After doing some online searching I'm still not sure how to wire this? Anybody have experience with one of these? Thoughts on what to try?

 

[m_m70]

thinking these were from vintage boats and used a sender.

I'm not an electrical guy by any means but if I were to try it, I would try neg side (green) to tach signal and pos side (red) to switched power and see what happens. Other wires are for the light.

Sure someone here has played with these before and will hopefully chime in.
Like the tach!!

 

[Bajabrewer]

thinking these were from vintage boats and used a sender.

I'm not an electrical guy by any means but if I were to try it, I would try neg side (green) to tach signal and pos side (red) to switched power and see what happens. Other wires are for the light.

Sure someone here has played with these before and will hopefully chime in.
Like the tach!!

Thanks for the response - Looking things over I was thinking the same as far as Red to Pos switched and green to the Tach port(which should be Neg) but I'm also not an electrical guy. I'm hoping to get in the garage later today & I'll report back.