Chevy Nova Forum banner

1 - 8 of 8 Posts

·
Registered
Joined
·
57 Posts
Discussion Starter · #1 ·
First off, Hello All and great site you have here.

So with that said I have an autometer tach with a shift light that I'm trying to install in my 69 nova (inline 6 :( ), I installed it myself in my 03 mustang a few years ago but took it out after awhile. So I hooked the red up to a power wire that turns on when the key is turned, white up to the lamp fuse, black to the neg battier and green to the neg coil and it doesn't work.... the tach light turns on when I turn my lights on, when I turn the key to on the tach allows me to change the shift light RPM and once I turn the car on it should be giving me my RPM but instead it's still allowing me to change the shift light RPM without any glimpse of my RPM. Any suggestions would be much appreciated? To be honest I think the tach is broken and I'm pretty sure I don't have an HEI but then again I'm new to the classic car world.


-Allan
 

·
Registered
Joined
·
1,659 Posts
Some of those AutoMeter tachs need a special inline resistor for them to work off the negative terminal of a points style ignition. The resistor goes between the negative terminal on the coil and the green wire to the tach and changes the signal the coil is giving out. Found that out on my car last year when I got a new Autometer tach. It has something to do with the signal the coil is giving out. You need a straight wave signal going to the tach but the coil is sending out a occilating signal or something stupid like that. I have the resistor if you would like to try it. I no longer need it since I recently upgraded to a new MSD 6al ignition. Let me know
 

·
Registered
Joined
·
57 Posts
Discussion Starter · #5 ·
Some of those AutoMeter tachs need a special inline resistor for them to work off the negative terminal of a points style ignition. The resistor goes between the negative terminal on the coil and the green wire to the tach and changes the signal the coil is giving out. Found that out on my car last year when I got a new Autometer tach. It has something to do with the signal the coil is giving out. You need a straight wave signal going to the tach but the coil is sending out a occilating signal or something stupid like that. I have the resistor if you would like to try it. I no longer need it since I recently upgraded to a new MSD 6al ignition. Let me know

hmm you're right I might need a resistor, let me look into it and let you know. I did check the tach by tapping the pulse wire (green) to the + battier for a second and the needle moved from one side to the other so I know it's working.
 

·
Registered
Joined
·
57 Posts
Discussion Starter · #8 · (Edited)
FIXED IT!! ok so I called Auto Meters tech support and after going over everything I've tried with the guy he told me to switch the green wire to the POSITIVE + coil side, so I did and it works fine now, he said sometimes crossed wires somewhere will cause this....so now with that fixed, should I be worried that my coil is turned around? Thanks
 
1 - 8 of 8 Posts
Top