tach wiring question
So I've browsed quite a few threads on the topic and I understand that the signal wire from the tach needs to go to the negative side of the coil. I've also read that the non tach to with tach cluster is just a direct swap. I'm trying to wire an aftermarket tach so my question is can I tap into that wire behind the dash without removing the cluster? and how does one find that wire?
92 F-150 super cab 2wd 4.9L I6 automatic.
Current project- Using the under hood fuse/relay box from a 97 Ranger to run any and all accessories (HD headlight harness high and low beam relays, fog light relay -eventually-, radiator E-fan relay -eventually-, A/C condenser E-fan relay -eventually-). http://www.f150forum.com/f10/whiter-...ne-mod-254956/