# do I need a tach adapter for... **URL:** \ **Category:** NYSpeed Automotive\ **Created:** [August 22, 2006, 9:23am UTC](https://forums.speedlife.net/t/do-i-need-a-tach-adapter-for/16295 "2006-08-22T09:23:22Z")\ **Posts on this page:** 4\ **Page:** 1
**Author:** ![drvnkd](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/drvnkd/32/109615_2.png) [@drvnkd](https://forums.speedlife.net/u/drvnkd)\ **Post date:** [August 22, 2006, 9:23am UTC](https://forums.speedlife.net/t/do-i-need-a-tach-adapter-for/16295/1 "2006-08-22T09:23:22Z")
do i need a tach adapter to run the MSD digital window switch on a GM 2.4l dohc? i;m told it’s the pink wire on the IDI harness, but i’m curious as to weather or not i’ll need an adapter. ?? ---
**Author:** ![articzap](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/articzap/32/7361_2.png) [@articzap](https://forums.speedlife.net/u/articzap)\ **Post date:** [August 22, 2006, 9:24am UTC](https://forums.speedlife.net/t/do-i-need-a-tach-adapter-for/16295/2 "2006-08-22T09:24:54Z")
i believe the 2.4 needs a tach adapter otherwise itll only read half the rpms…i cant remember for sure though ---
**Author:** ![drvnkd](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/drvnkd/32/109615_2.png) [@drvnkd](https://forums.speedlife.net/u/drvnkd)\ **Post date:** [August 22, 2006, 9:39am UTC](https://forums.speedlife.net/t/do-i-need-a-tach-adapter-for/16295/3 "2006-08-22T09:39:39Z")
it reads 1/2 because of the wasted spark… the MSD has a setting for 2 cylinder waste spark… i just dont know if it works as is… ---
**Author:** ![drvnkd](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/drvnkd/32/109615_2.png) [@drvnkd](https://forums.speedlife.net/u/drvnkd)\ **Post date:** [August 23, 2006, 4:44am UTC](https://forums.speedlife.net/t/do-i-need-a-tach-adapter-for/16295/4 "2006-08-23T04:44:06Z")
nevermind… once connected to the white wire of the IDI harness, it read rpm just fine.