Two quick tach questions
Thread Starter
Heel & Toe
Joined: Dec 2008
Posts: 17
Likes: 0
From: Omaha Nebraska
Two quick tach questions
I just spent some time working on my tach this last weekend. When I finished some how I managed to get the tach reading and responding again.
1. I removed the tach filter because it was causing a voltage drop from 12volts to 9 volts. Do I need it/ is this normal?
2. How would one find out if the read out on the tach is calibrated?
Thanks in advance.
1. I removed the tach filter because it was causing a voltage drop from 12volts to 9 volts. Do I need it/ is this normal?
2. How would one find out if the read out on the tach is calibrated?
Thanks in advance.
Former Vendor
Joined: Apr 2009
Posts: 766
Likes: 3
From: Charlotte North Carolina 704-394-5150
Question 1.) If you replaced the original tach board with an aftermarket tach board ( the one that is mounted on the back of the tach). I was told my the guy who makes them, that you do not need the tach filter.
Question 2.) If you have access to another electric tach that you know is good. You can remove the factory tach wire going into your distributor cap. Crimp on an electrical spade connector that has two wires in it. Connect one wire to you factory wiring and the other to the "good tach" where tha tach wire should be conneceted. Then add a ground wire the good tach. Using a wire with a in-line fuse, connect it to the good tach where the 12 volt power is to be connected and connect the other end to a 12 volt power source and crank it up and check the readings. The factory tach filter had ( or should have had) an extra wire coming out of the connector that went into the distributor cap connector just for that reason. So you could have a tach inside the engine compartment while doing some repairs. I hate to have you cut your tach filter apart for the wires but some of my customers have done that in the past instead of making their own new wires/connectors.
Question 2.) If you have access to another electric tach that you know is good. You can remove the factory tach wire going into your distributor cap. Crimp on an electrical spade connector that has two wires in it. Connect one wire to you factory wiring and the other to the "good tach" where tha tach wire should be conneceted. Then add a ground wire the good tach. Using a wire with a in-line fuse, connect it to the good tach where the 12 volt power is to be connected and connect the other end to a 12 volt power source and crank it up and check the readings. The factory tach filter had ( or should have had) an extra wire coming out of the connector that went into the distributor cap connector just for that reason. So you could have a tach inside the engine compartment while doing some repairs. I hate to have you cut your tach filter apart for the wires but some of my customers have done that in the past instead of making their own new wires/connectors.
Thread Starter
Heel & Toe
Joined: Dec 2008
Posts: 17
Likes: 0
From: Omaha Nebraska
Thanks for the help. Any suggestions on where to borrow a good tach? 
I think I remember a post where people wanted to have a traveling tach. My guess is that nothing ever amounted of that effort.
I think I remember a post where people wanted to have a traveling tach. My guess is that nothing ever amounted of that effort.
