hey guys... here's my issue:

My speedo (digital) keeps going from reading an accurate speed to reading zero. Its not the power supply.... it stays lit and bright the whole time. In an effort to remedy this problem I have done the following:

1. Replaced the speedo cable (and visually inspected it prior to instalation)
2. Replaced (with a used) the speed sensor.

It still reads zero now and then and when it reads zero my auto transmission button for the passing gear (no overdrive) wont work and it doesn't like to downshift.

I'm not sure what the deal is. Please let me know if you can help... i need this fixed pronto as I'm selling my car!

 

Did you replace the pinion gear seals at the same time? Chances are you are leaking transmission fluid up the cable and gumming up the speed sensor.

 

Here's the deal... when I replaced the speed sensor (with another used one) and drove off... it read zero for a while then kicked on (no change from before I installed the sensor) which leads me to believe the problem was not with the sensor and that it wouldn't have had time to gum it up. Is there a way to clean the sensor out?

 

I would guess a failing diode or resisitor in the printed circuit on the cluster. Either that or a really coroded connection somewhere. You may need to just pull the thing apart, clean it out with electrical circuit cleaner and compressed air then see where it goes.

 

pull the dash apart???

 

Well, the cluster assembly. It comes out by itself.

 

IT DOES!!!??? Awesome.... Any tips on getting it out without removing the dash?

 

what az-bum said.........again---could still be leaky.....

 

how can I tell if its gummed up... also... if it is gummed up how do I ungum it. Here's the thing... if it gummed up the first speedo sensor and i installed the new one and it read zero as soon as I pulled out would that point to something else? It the pinion seal the clearish plastic part that slides around on the transmission end of the speedo cable or is it in the transmission? If this is not it (gummed speedo sensor) does anyone have another idea?

 

the speedo sensor wasn't wet in the slightest nor was the cable. There was nothing to drain or anything. I'm thinking pinion gear now... any other ideas? Please... I need help quick (thank you everyone for your help so far).

 

Maybe you should take it to a Nissan dealer / mechanic.

 

exactly what I was looking for...