Help needed-speedometer

[Abchameleon]

04 ford sport trac xlt 4wd auto. Speedometer and cruise control not working. Check fuses all good. Replaced vss on rear diff did not fix, sent instrument cluster for repair all other gauges work speedometer Still not working. No check engine light, no codes when scanned. Could the output sensor on transmission be the issue? When i went to part store for vss they originally gave me part on transmission but I was told the vss is actually the one on rear diff that was replaced. Transmission is shifting fine. Side note the 4x4 low light does stay on dash but I have never used 4 wheel drive not sure if this would be connected. Major concern is speedometer.

 

[icthusrulz]

What exactly do you mean by your speedometer not working?

If I recall correctly, the PCM gets the signal that the transfer case is in “4x4 Low” from the 4Low switch circuit in the transfer case that illuminates the light on the dash. When this happens it should change the speedometer calibration for 4Lo, disable cruise control and disable the ABS system.

You might try disconnecting the wire at the 4Low switch on the transfer case to see it that fixes your problem.

If that does fix it you’ll have to diagnose why the switch is activating when you are NOT in 4x4 Low.

 

[Abchameleon]

What exactly do you mean by your speedometer not working?

If I recall correctly, the PCM gets the signal that the transfer case is in “4x4 Low” from the 4Low switch circuit in the transfer case that illuminates the light on the dash. When this happens it should change the speedometer calibration for 4Lo, disable cruise control and disable the ABS system.

You might try disconnecting the wire at the 4Low switch on the transfer case to see it that fixes your problem.

If that does fix it you’ll have to diagnose why the switch is activating when you are NOT in 4x4 Low.

When driving the speedometer does not register any speed. The needle doesn't move from zero. As for the 4x4 low light it has been on for years the speedometer just recently stopped working.

 

[koda2000]

When driving the speedometer does not register any speed. The needle doesn't move from zero. As for the 4x4 low light it has been on for years the speedometer just recently stopped working.

In that case I'd guess your VSS (vehicle speed sensor) is responsible for the cruise control, your speedo and odo issues. Older models VSS is located on top of the rear diff, but IDK where it would be on an '04. Does the '04 have IRS or does it still have leaf springs?

 

[Abchameleon]

When driving the speedometer does not register any speed. The needle doesn't move from zero. As for the 4x4 low light it has been on for years the speedometer just recently stopped working.

Removed the fuse for 4wheel drive motor and speedometer is working. Seems the issue is with the 4 wheel drive. Thanks for your help!