Speedometer going in and out.

[Zagnut187]

Hey y'all,

95 Ford Explorer Limited.

Took it to my shop and they said I needed a speedometer head($550+).

No codes on diags.

However, after reading this thread: http://www.automotiveforums.com/vbulletin/t150530.html

The speedo works sometimes, the odometer works fine.

I am now thinking the VSS drive gear ($25.00) is the problem.

Any help will be much appreciated.

Thanks guys!

Edit:

I also found this:
It could be the Vehicle Speed Sensor/Cruise Control Transducer. You can test it easily enough. Of course if the problem is intermittent the test will be inconclusive.

2. Disconnect speed sensor connector, then connect an ohmmeter between dark green/white and black wires.
3. A reading of 180-250 ohms should be obtained. A reading of 0 ohms indicates a shorted coil and an infinity reading indicates an open coil.
4. Replace sensor if a proper reading has not been obtained.

The VSS is located on the output housing of the transmission or the transfer case with all wheel drive.
The Vehicle Speed Sensor (VSS) is a magnetic pulse generator driven by the transmission speedometer gear. The VSS produces 16 AC signals per revolution and sends this signal to the Powertrain Control Module (PCM).
The PCM converts this signal to a vehicle speed value and stores that value in RAM memory. The PCM uses this value to aid in controlling torque converter lock-up, coolant fan control, vehicle speed control, air/fuel ratio and ignition timing.

[shorod]

Does your cruise control work, even when the speedometer is not working?

So, even when the speedometer doesn't work, the tachometer continues to work?

-Rod

[Zagnut187]

Yes the cruise still works even when the speedo does not.

The tach works.

Update: I have more problems. After being in the shop, the truck bounces violently even when going 30mph. I think they didn't turn the air ride off when they put the truck up on the lift. Is this something that needs to be calibrated?

[tseymour]

The speedo in my wifes explorer did the same thing. Her's is a 98 AWD. The plastic circuit board on the back of the dash seperates and does not make connection. I pulled it apart and added jumper wires from the connector to the speedo and have not had a problem since

[Zagnut187]

I will try that. Is it a pain to tear the dash out?

Another thing I noticed in the paperwork is that the trany has been replaced recently. Is this anywhere near the VSS? Would it be worth replacing that anyways?

Thanks all!

[tseymour]

I don't know about the VSS. and yes the dash is a pain to take out. But cheaper than $550.00