1994 Nissan Pick up speedo problem

[phil.higgs]

1994 Nissan pick up. Speedometer random. Sometimes reads 120 mph when going 55 mph . Sometimes reads 0 mph when going 40 mph. How to diagnos accurately? Speed sensor or speedometer head or wiring?

[Eikon]

Good question Phil.

Welcome to NICO by the way. Hopefully we can help you out.

I would guess that you have a bad ground or poor electrical connection somewhere. Check out the speed sensor on the trans and just make sure the wire clip is on tight. Try to pull it off and make sure it's clean. Try bending the metal connectors a tad just to make sure you are getting good contact. If that doesn't help, try pulling the dash and checking the connections on the cluster.

I doubt that a speed sensor is very expensive for a hardbody pickup trans.. you might try replacing it if you don't find a wiring problem.

Hope this helps.. let us know if you dig into a little further.