[johnta1]

I guess I should have asked 1st how is the tach supposed to be wired?
Does it need 12 volts to make the tach work?

Don't know what Hyperspark is.

Stock just uses a wire to coil and a ground wire.
A 12 volt source is just used for the light. (usually for nighttime)
3 wires total. (unless housing is the ground then just 2)

Also what car and year?

[TheCeleryStalker]

Originally Posted by johnta1

I guess I should have asked 1st how is the tach supposed to be wired?
Does it need 12 volts to make the tach work?

Don't know what Hyperspark is.

Stock just uses a wire to coil and a ground wire.
A 12 volt source is just used for the light. (usually for nighttime)
3 wires total. (unless housing is the ground then just 2)

Also what car and year?

It's 3 wires and was originally wired to the wiper motor, the coil negative, and ground.

Hyperspark is Holley's HEI distributor, coil, etc. It has a wire out that is supposed to work with these old style tachs. Its crazy to me that wired the same way (except not to the coil, but to the tach out), it works but only with wipers on.

Maybe, I do need that tach adaptor.