Speed sensor signal problem

Getting really fed up with this. Did a box swap about 8 weeks ago, since then the speedo hasn't worked.

Problem:
Gearbox taken out of car has a separate plug in speed sensor.
Gearbox put in car is a later version with speed sensor integral in the box. The wiring loom is different on the new gearbox.
From this site I got wiring diagrams that showed both gearbox set-ups and it seemed a pretty simple job to take the signal wire from the 'new' gearbox and link to the loom on the car that had the plug in sensor.

We have a pulse from the gearbox sensor, but when connected to the car wiring loom, the speedo still isn't driving!

Are there differences between earlier and later speedo heads or speed sensors?

HEEEELLLLLPPPPPPPPPPPP!

[mohrds]

Originally posted by TonyShaleUK
Getting really fed up with this. Did a box swap about 8 weeks ago, since then the speedo hasn't worked.

Problem:
Gearbox taken out of car has a separate plug in speed sensor.
Gearbox put in car is a later version with speed sensor integral in the box. The wiring loom is different on the new gearbox.
From this site I got wiring diagrams that showed both gearbox set-ups and it seemed a pretty simple job to take the signal wire from the 'new' gearbox and link to the loom on the car that had the plug in sensor.

We have a pulse from the gearbox sensor, but when connected to the car wiring loom, the speedo still isn't driving!

Are there differences between earlier and later speedo heads or speed sensors?

HEEEELLLLLPPPPPPPPPPPP!

It is the same speed sensor part number listed for all years (85082PA010) so there should not be any difference there.

Just for test, if you have the old speed sensor, hook it into a drill and spin it fast to see if the speedo reads. You may have developed a harness failure during the physical change.

Have you checked for Speed sensor pulse at the ECU? That should tell you if the harness is OK or not. I don't remember off the top of my head what pin it is on the ECU, but I'm sure someone will jump in with it.

By the way, what gearbox did you install? I did not know that any SVX trannies had an internal speed sensor.

Doug

Thanks Doug,

I'll try the drill test - I assume that it is obvious how to do it?!

Where is the ECU located? I have the wiring diagrams showing which pin of the TCU takes the input from the sensor.

Tony

Forgot to mention the tranny - it was from a 92 UK car, but replaced in about 1998 by Subaru main agent. Looks like the same casing, but obviously different in terms of the sensor - I have the wiring diagram from a 1994, I think and that shows the internal sensor.

[mohrds]

Originally posted by TonyShaleUK
Thanks Doug,

I'll try the drill test - I assume that it is obvious how to do it?!

Where is the ECU located? I have the wiring diagrams showing which pin of the TCU takes the input from the sensor.

Tony

On the US models, it is under the left side dash, strapped to the TCU. On the RHD vehicles, I woud assume it would be under the right side dash.

As for the drill test. It is pretty obvious. There is a little shaft sticking down that spins...

Doug