Gold Lifetime Member
Join Date: Dec 1999
Location: Yorkville, Illinois USA
A couple of years ago, I put an aftermarket tach on my Blazer. The tach came with an adjustable capacitor. The instructions said if the tach was jumpy, wire the capacitor between the tach signal wire and ground, and adjust it until the needle smoothed out. The tach was jumpy, I put the cap in and adjusted it, works perfect now. You can get one at radio shack, get a 1000 mfd adjustable capacitor (it's very little.)These thing are meant to mount on a pc board, so put it in a safe place, adjust it, and then tape it up so it can't short out.