[fordnut]

I have a Mallory 5" tach (us old men need a big tach to be able to see it) Have had it in the car for 3 years. Ever since the 460 swap, can't get it to work right. It works at Idle, but, falls to 0 when you rev the motor....I through the wiring instructions away a long time ago. (A guy thing...I don't need no stinkin instructions) Anybody got an idea how to wire this thing up so it will work.....
Thanks

 

[Shaun]

My tach has 4 wires.

Red - 12v source
Green - Negative side of the coil
Black - Ground
White - lights

Could it be you have it wired to the wrong side of the coil?

 

[fordnut]

I tried it on the other side of the coil, but, with no luck....I will try it again....

Thanks
Steve

 

[JSHarvey]

If you've switched sides on the coil connection you may have fried the insides of the tach. It would have received quite a few more volts than it was "expecting" in that case. :-(

John

 

[fordnut]

Hey guys Thanks a lot. I got it fixed. Had a bolwn fuse at the box where I was pulling power. Replaced fuse and it works great....appreciate the help.

Steve (Fordnut)

 

[Shaun]

Ta-da!!!