TheRktmn

Check that the coil is not wired backwards. I have seen many coils with + (IGN) and - (DIST) posts wired wrong. The car will run that way, but not that well. Easy way to make sure: Take the wires off the coil. Turn on key switch. Wire with voltage goes to positive + (IGN) side of coil. Wire coming from distributor with no voltage goes to negative - (DIST) side of coil. Edit: 20V? Wow!

Reminds me of the old Heathkit antennae mounts for ham radios.

My tach wires like so: Black to ground - you can ground it to the back of the cluster. Red to switched power - you should be able to connect it to the jumper you put on the original tach plug. Green to - side of coil.

That white device is an external ballast resistor. Chances are it was installed for 1 of 2 reasons: 1. The original resistor wire failed. 2. They wanted to get 12V for a Pertronix Ignitor or other device, but still needed reduced voltage to the stock coil. If you are running a Pertonix Ignitor you can power it off the ballast resistor input side (the stud not wired to the coil), and ground it to the block. Note that when using the external ballast resistor you need to run a new non ballasted wire from the ignition switch to the resistor. (in the future, please try not to

You are using one of my wiring diagrams (Rocketman) to install a Tachman tach? Interesting. The jumper I refer to in my instructions is to connect the two wires in the OEM tach connector to complete the primary circuit from ignition switch to coil +. I would have sent the original tach pigtail back so that you can use it to make the jumper.

I've been running Magnum 500s since 1979 on 4 different vehicles on both street and strip. No issues at all.

Video of testing Ford G1:

NPD has reproductions: No tach: https://www.npdlink.com/product/printed-circuit-dash-gauge/100964?backurl=search%2Fproducts%3Fsearch_terms%3Dprinted%2Bcircuit%2Bassy%26top_parent%3D200001%26year%3D1971&year=1971 With Tach: https://www.npdlink.com/product/printed-circuit-dash-gauge/100965?backurl=search%2Fproducts%3Fsearch_terms%3Dprinted%2Bcircuit%2Bassy%26top_parent%3D200001%26year%3D1971&year=1971

Cut it in half, fold it in half, anything that makes it unusable so they have proof that you are not getting a 2 for 1 deal.

Best ways are to contact Randy at Midlife Harness ( http://midlifeharness.com/ ) and have him redo the cluster wiring and have me convert your ammeter to voltmeter - Randy can help with the wiring there too.

Unresisted (Full 12V) voltage will make the tach inaccurate (read high) and shorten the life of the tach.

Yes you can.

I have a Holley on my 460. It is basically a Carter. On my Clevelands I ran a stock pump with an electric for when I was racing.

I ordered, selected Guest rather than give more info to fakebook, selected PayPal and never saw a place to put in my THANKS20 discount code. Oh well, I'll try again next year.

I THINK the differences are: P1 - Works with stock wiring, but can burn out if key is left on with engine off. P2 - Requires 12V feed but has protection against the 'key on' failure. P3 - Same as P2, added multiple spark and rev limiter. Having had to deal with the Pertronix devices with my tach movements I am not a fan of Pertronix Ignitors. Put one on a scope sometime and you will be amazed - voltage swings of 35+ volts at the coil! I switched over to Duraspark II years ago and love it. My second choice would be points.