which pin/wire on ECU has tach signal on it?

[tording]

I am looking a pin/wire that goes into the ECU that has a tach signal on it. I want to tap into it for a window switch. Anybody know what pin it is? thanks in advance.

 

[jrichker]

Try using the IDM, pin 4, dark green/yellow wire. Be careful that your window device does
not load the signal excessively, or you will set a code and the tach readings will be off calibration.

Diagram courtesy of Tmoss & Stang&2birds

See the following website for some help from Tmoss (diagram designer) & Stang&2Birds (website host) for help on 88-95 wiring http://www.veryuseful.com/mustang/tech/engine/ Everyone should bookmark this site.

Ignition switch wiring
http://www.veryuseful.com/mustang/tech/engine/images/IgnitionSwitchWiring.gif

Fuel, alternator, A/C and ignition wiring
http://www.veryuseful.com/mustang/tech/engine/images/fuel-alt-links-ign-ac.gif

Complete computer, actuator & sensor wiring diagram for 88-91 Mass Air Mustangs
http://www.veryuseful.com/mustang/tech/engine/images/88-91_5.0_EEC_Wiring_Diagram.gif

Vacuum diagram 89-93 Mustangs
http://www.veryuseful.com/mustang/tech/engine/images/mustangFoxFordVacuumDiagram.jpg

HVAC vacuum diagram
http://www.veryuseful.com/mustang/tech/engine/images/Mustang_AC_heat_vacuum_controls.gif

 

[tording]

Maybe I don't want to do that then if its going to cause issue's. Anyone know why my zex window switch would not be picking up the tach signal off the negative side of the coil properly? I was told to hook it there and I did but its not reading the signal properly. Zex tech support told me to hook the tach wire up at the ECU to see if that works but I don't want to cause other problems.