Speedo Not Working!

[Vexy]

I did a MT (M5R1) swap on my 96 Mazda B4000 4x4. Transmission was from a 95 B4000 4x4, I have a 1996 MT ECU swapped in, as well as a MT Transmission harness. The speedometer does NOT work though, nor does the odometer. Both VSS's are new and tested good. Gauge cluster is new as well. Checked fuses, and continuity. What else could be the problem?
Any tests that could help me track down the problem? I really need this speedo working ASAP for emissions testing!

 

[RonD]

I think your year has a GEM, Generic Electronic Module, it is used for the speedo as well as other electric controls, this is a programmable module, where the transmission, tire sze and gearing are entered to get a correct speedo reading.

Not sure of any test to confirm it is working, it's location should be behind the radio, either slightly to the left or right of center.

 

[Andy D]

Pretty please , Ron , tell me the 94 Rat doesnt have this modern stuff

The truck runs so freaken good , I just know some old Ford thing will rear its head.

 

[adsm08]

Ok, your speedo gets power from fuse 25 of the interior fuse panel, and gets a variable reluctance signal on the ground side through the VSS.

I would unplug the cluster, and hook up a volt meter, preferably analog for this, to pin 4 white/yellow on the positive and pin 12 gray/black on the ground, jack up the rear, and run it. See what the needle does. If it varies proportionally to your speed you have a cluster issue.


Andy, have no fears. 1994 was the last year of the cable driven speedometer in the Ranger.

 

[Vexy]

Ok, your speedo gets power from fuse 25 of the interior fuse panel, and gets a variable reluctance signal on the ground side through the VSS.

I would unplug the cluster, and hook up a volt meter, preferably analog for this, to pin 4 white/yellow on the positive and pin 12 gray/black on the ground, jack up the rear, and run it. See what the needle does. If it varies proportionally to your speed you have a cluster issue.


Andy, have no fears. 1994 was the last year of the cable driven speedometer in the Ranger.

No voltage at all!

 

[Vexy]

The M5R1 is from a 1995 Mazda B4000 4x4
Transmission Harness came off a 1995 Ford Ranger 4x4 MT

And the PCM is off a 1996 Ford Ranger 4x4 4.0L MT (F57F-12A650-DAC)
Could the problem be the PCM not being compatible with something? Like my GEM for example?