Tach Troubles

Fuelie74

Well-known member
Joined
May 7, 2008
Messages
770
Location
Monroe, WI
My 74 has had an electric tachometer out of a 75-77 since I got that car and it has never worked. While I had the dash out this spring I decided that it was time to fix the tach so, I bought a new circuit board and tach filter from Wilcox. The tach works now but, the needle bounces badly on rapid engine rpm change. Other than that it seem fairly accurate. It has got better some now that I have been driving it but, its still not good. So is there anything I can do for this thing other than send it off somewhere for repairs?
 
YES, you need to buy or make a 'tach filter' it was put into the tach line from the dizzy , mounted to engine just under the dizzy, that gave it a ground through the bolt...it's a minor electronic circuit called a PI filter....or L/C network if you will....

if you need a schematic I can look around to find one and email it to you, maybe it's on this computer to send...but it's been a while...

do you know how to solder wires?? if so, it's easy, just two resistors and two caps....I built mine about 15 years ago, still in action...

:cool:
 
Found my issue toady. Turns out Willcox had a problem with a capacitor in a batch of boards and I happened to be on of the lucky ones to get one.

I emailed them with the problem after reading a thread on CF with a similar issue. They emailed me back and said my board would of been in the time frame that they had some bad ones get out. They said to send the board back and they would send me a new one and said that if I wanted to mail them the tach that they would install the board and calibrate the tach for me free of charge.

So the good news is my tach will be fixed. To bad I have to take the dash apart again.:banghead: I am very happy with there response though!
 
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