# How to find rpm/tach signal **URL:** \ **Category:** NYSpeed Automotive\ **Created:** [June 3, 2010, 4:30am UTC](https://forums.speedlife.net/t/how-to-find-rpm-tach-signal/155967 "2010-06-03T04:30:44Z")\ **Posts on this page:** 7\ **Page:** 1
**Author:** ![ultradriver10000](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/ultradriver10000/32/7397_2.png) [@ultradriver10000](https://forums.speedlife.net/u/ultradriver10000)\ **Post date:** [June 3, 2010, 4:30am UTC](https://forums.speedlife.net/t/how-to-find-rpm-tach-signal/155967/1 "2010-06-03T04:30:44Z")
A buddy of mine has a 2007 Ram and we are hooking up a shift light and n20. I’m going to be using a msd digital window switch. Both the shift light and the msd need a rpm input. Does anyone know where I can find this coming out of the ecu or engine bay area? Thanks!! ---
**Author:** ![MaximaSE98](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/maximase98/32/7600_2.png) [@MaximaSE98](https://forums.speedlife.net/u/MaximaSE98)\ **Post date:** [June 3, 2010, 5:12am UTC](https://forums.speedlife.net/t/how-to-find-rpm-tach-signal/155967/2 "2010-06-03T05:12:24Z")
u could try the crank position sensor…i know a few people atleast in the Sentra Spec V community have been using that with SAFCs for tuning quite sucessfully ---
**Author:** ![newman](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/newman/32/7569_2.png) [@newman](https://forums.speedlife.net/u/newman)\ **Post date:** [June 3, 2010, 5:49am UTC](https://forums.speedlife.net/t/how-to-find-rpm-tach-signal/155967/3 "2010-06-03T05:49:11Z")
Since the gauge cluster is can/bus, there is probably no dedicated tach signal, however, you should be able to grab it from a coilpack pulldown, but you need an MSD tach adapter. I’d be hesitant to pull the info of the CAS… ---
**Author:** ![quadturbo](https://avatars.discourse-cdn.com/v4/letter/q/7bcc69/32.png) [@quadturbo](https://forums.speedlife.net/u/quadturbo)\ **Post date:** [June 3, 2010, 8:58am UTC](https://forums.speedlife.net/t/how-to-find-rpm-tach-signal/155967/4 "2010-06-03T08:58:17Z")
I found this on [the12volt.com](http://the12volt.com) not sure if it will work. Tachometer dk. blue/gray ac PCM, black/orange plug, pin 34 Notes: The PCM is on the passenger side firewall. The black/orange plug is the second plug down from the top. ---
**Author:** ![Haenszel](https://avatars.discourse-cdn.com/v4/letter/h/e68b1a/32.png) [@Haenszel](https://forums.speedlife.net/u/Haenszel)\ **Post date:** [June 3, 2010, 9:10am UTC](https://forums.speedlife.net/t/how-to-find-rpm-tach-signal/155967/5 "2010-06-03T09:10:20Z")
> [@newman](#): > > Since the gauge cluster is can/bus, there is probably no dedicated tach signal, however, you should be able to grab it from a coilpack pulldown, but you need an MSD tach adapter. > > I’d be hesitant to pull the info of the CAS… if you do this, then tell the software you’re running a 1cyl engine it will work. ---
**Author:** ![dirtye30](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/dirtye30/32/7333_2.png) [@dirtye30](https://forums.speedlife.net/u/dirtye30)\ **Post date:** [June 3, 2010, 1:59pm UTC](https://forums.speedlife.net/t/how-to-find-rpm-tach-signal/155967/6 "2010-06-03T13:59:09Z")
grab an injector wire, and program for 1 cyl ---
**Author:** ![ultradriver10000](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/ultradriver10000/32/7397_2.png) [@ultradriver10000](https://forums.speedlife.net/u/ultradriver10000)\ **Post date:** [June 3, 2010, 3:30pm UTC](https://forums.speedlife.net/t/how-to-find-rpm-tach-signal/155967/7 "2010-06-03T15:30:08Z")
Thanks for the tips when I get back in town I’ll be toying with this again.