The speedometer in my 1992 W250 isn't working right. When I go down my drive way it says I'm going 90 mph when really I'm going like 5mph. Does anyone know how I could fix it?

 

When that happens do the miles click off like you are really going 90?

 

No, the needle just goes crazy.

 

I am pretty sure that the speedo itself is the problem. But someone who knows for sure will chime in.

 

ok, Thank you!

 

Make sure the VSS is not loose.

 

I don't know a whole lot about this kinda stuff, how do I get to the VSS?

 

It's on the transmission (2wd) or transfer case on the driver's side. Make sure the nut that holds it on is not loose and that the electrical connection isn't cruddy. Follow the wiring harness up under the truck and make sure it's not chafed and rubbing.

 

ok I'll check that out.

 

I have 4wd manual transmission, will that make a difference?

 

The only difference is that the vss is on the transfercase. It will be on the driver side and it has 3 wires comming out of it. It will be near the rear drive shaft output. It is not the 3 wire connector up by the shifter linkage that is the nss.

 

Only 2wd auto trucks have 3 wires. All others are 2 wire VSS's.

 

Wow I never knew that sorry for the bad info.

 

lol thats ok, I'll check it out as soon as I can

 

took it apart and cleaned it out, everything seems to working the way it should be! Thanks for the help!