Old Autometer Tach

Electrical and Ignition

  1. ‘69_Sunfire_RR

    ‘69_Sunfire_RR Active Member

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    Hello everyone,

    Question, I have an old Autometer tach from the 60’s (I believe based on markings inside) that I’ve decided to try and use in my car. My intent was to stay period correct if possible. It is a two-wire tach that puzzles me a little. It has a (+) and (-) terminal on the back of the tach. Two other studs for mounting. An Autometer sender, model 84V, is mounted to the back and terminated at the (+) and (-) terminals on the tach. On the sender it has a terminal called ‘Dist Pri’ for the signal and a terminal for ‘grd’ Or ground. So I wired the ground to my grounding lug on the engine block. This ties directly to the ground terminal on the battery. My car came with a Summit ‘Ready to Run’ billet distributor and Summit coil. The distributor had a three wire harness—-ground which is tied to the block, red wire which terminates at the coil + and an orange wire to the coil negative terminal. I tied the ‘dist pri’ of the tach to the negative side of the coil with the orange wire from the distributor. When I turn the key, I see the needle on the tach go to zero. Starting the car it appears to show the proper RPM level at idle (650 RPM or so). Then the needle just gradually climbs and goes as high as 5000 RPM. Again the engine is still idling. Turn the car off, it goes to zero. Start the engine, the same occurs. Anybody ever seen this occur? It could be the sender or perhaps I just use this old tach with this style dizzy? Just wondering if you all have any advice. I have two of these tacos and they’re really a nice period correct addition. Perhaps I can have a more modern movement put in this unit?

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    RonLiv likes this.
  2. Russ69Runner

    Russ69Runner Well-Known Member

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    Green is the signal wire hooked to the negative side of coil. This is what I saw on the Autometer Tach on the internet. Red hot- white for the light. They say contact Autometer and they will help you with the wiring. So they must still make them. I would think new or old they should wire the same. But some thing is not rite for it to do what it is doing. Hope they can help ya. Russ.
     
  3. ‘69_Sunfire_RR

    ‘69_Sunfire_RR Active Member

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    Thank you Russ!
     
  4. Russ69Runner

    Russ69Runner Well-Known Member

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    Hope this helped. My Tach on my Harley wired to the green wire. Being an electrician would think green would be ground to the frame. They use the wires they want and pick the color code for the unit the produce. Let us know how it work's out. Russ.
     
  5. ‘69_Sunfire_RR

    ‘69_Sunfire_RR Active Member

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    Tough part here is that there is only two wires (actually just two lugs), well three with the wire going to the bulb. So you have a signal wire lug on the sender and a ground on the same sender. That’s all. So the wire coloring has no play here, As I just have lugs on the sender which is attached to the back of the tach. After looking more at this I need a filter circuit in line with the signal wire. The hei ignition is sending too much noise to the tach that’s why the needle is floating after I start the car. I’m going to build a filter circuit or buy a pre-fab tach filter circuit from classic industries. I think this solves it but I’ll respond here once I’ve tried it. Thanks for all of the advice!
     
  6. Russ69Runner

    Russ69Runner Well-Known Member

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    I try to help if I can. Sound's like you have a handle on the problem. Keep us informed on how it works out. :thumbsup2:
     
  7. quikbird

    quikbird Well-Known Member

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    Msd makes a filter for this
     
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  8. Rich B

    Rich B Well-Known Member

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    Tac’s a must. The Pontiac hood tack worked out great for me, never an issue. Could actually watch road and tach at same time. What was the redline for the 383- 5,800 if I remember right. Excellent reproductions out there today and definitely period correct.

    Reminds me of the HUD out these days, shows up on windshield (heads up display).

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  9. Russ69Runner

    Russ69Runner Well-Known Member

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    Their is a Pontiac tach on your runner. Holly S------. Tell me its not so. Well if it work's for you then it is what it is. Just saying. I don't have runner seat's in my car bought scat seat's bucket's for my runner. They recline and have back support. It is better than the mustang seat's that came in it. Have fun Rich B. :thumbsup2:
     
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  10. Rich B

    Rich B Well-Known Member

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    Sorry Russ, didn’t mean to imply these days. Not my car, just what those looked like; think it was only 3 wires- lamp and 2 to coil, series thing and all open under hood. Way too long ago, remembering things I completely forgot about.
     
  11. Basketcase

    Basketcase Keeper of the Green

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    relax Russ..Mopar had'm too

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  12. Russ69Runner

    Russ69Runner Well-Known Member

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    I do remember seeing them and thought to my self what another hole in the hood. I would like to see some one that put them in the A pillar cover. Use to see them mounted on the dash after market that is. On the steering column and mounted in front of the console. So all that being said I am going to put one of the re pop one in where the clock goes. I don't have a clock so that is what is going to happen to this car. Thinking that is a wise choice. What do you think DAVE?????? :poke::mob:
     
  13. Basketcase

    Basketcase Keeper of the Green

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    bottom line...your car, do what makes you happy! Mine is strapped to the column.
     

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