Autometer Electric Speedo Help

[gcwh02]

I need help determining what to wire to the back of the speedo and what to leave out. I know I need to use the VSS but not sure what wire that is. Specific help would great. Thank you

 

[93 LX]

the VSS goes to the ECC unit. I am not sure which pin but thats where the signal goes. Since Mustangs Speedometers are mechanical there really isnt any reason for that signal to be at the guage package.

Without knows what year you have here is a site that may help you
http://www.veryuseful.com/mustang/tech/engine/

 

[Markus]

Hello,

i connect my speedo as followed........
The speedo and the vss works great.

Sorry for the crappy drawing.

Markus

 

[gcwh02]

thanks for the drawing, but where can I find the VSS or the wires I need to do this

 

[jrichker]

VSS is an electronic sender mounted on the speedo pickup gear on the trans. It works the cruse control for both 5 speed and auto trans cars. It tells the computer to speed up the idle slightly as you slow down to a stop to keep the engine from stalling.

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

TFI module differences & pinout
http://www.veryuseful.com/mustang/tech/engine/images/TFI_5.0_comparison.gif

Fuse box layout
http://www.veryuseful.com/mustang/tech/engine/images/MustangFuseBox.gif

 

[gcwh02]

So i splice into pin 3 for the signal (do I follow that off of the ECU?). And for pin 6, I see the diagram shows it goes to the ground--- does that mean that it is already grounded or do I need to ground it somewhere.

 

[jrichker]

So i splice into pin 3 for the signal (do I follow that off of the ECU?). And for pin 6, I see
the diagram shows it goes to the ground--- does that mean that it is already grounded or do I need to ground it
somewhere.

For best results, use both pins 3 & 6. One is signal + and the other is signal -.

The output of the VSS is a sine wave that does not use ground as a reference point. The computer's input for VSS
looks at difference in the signal between the + and - inputs to filter out some of the electrical noise that might fool
the computer. The computer uses the change in frequency as the vehicle speeds up or slows down to get vehicle
speed information.

 

[gcwh02]

so the best way to get to the wires is to unplug the plug from my ECU and find pin 3 and 6 off of the plug and splice into the wires from there?

 

[jrichker]

so the best way to get to the wires is to unplug the plug from my ECU and find pin 3 and 6 off of the plug and splice into the wires from there?

Yes

 

[defcondaze]

For best results, use both pins 3 & 6. One is signal + and the other is signal -.

The output of the VSS is a sine wave that does not use ground as a reference point. The computer's input for VSS
looks at difference in the signal between the + and - inputs to filter out some of the electrical noise that might fool
the computer. The computer uses the change in frequency as the vehicle speeds up or slows down to get vehicle
speed information.

yes, i know this is a old post...
i have to wire my electric speedo too ...
you say use both + and - signals .... how ?
there is only one signal on the new speedo .... i assume the + goes to that ... where does the - go ?

thanks !

 

[defcondaze]

bump