i was wondering if anybody has an aftermarket tach hooked up in their car and could offer some assistance with wiring one up. i was going through my closet and i came across a brand spankin new autometer tach and i thought i might as well just put it in my car to free up some space in my room. i hear you may need a tach adapter, and i heard you can tap it in the diagnostics box under the hood. but the idea of tapping into the diagnostics box sounds kinda iffy so i wanted to know if anybody has had any success of wiring it another way and without a tach adapter. any help would help me out big time and i'd greatly appriciate it. thanks.