HELP!!!! My speedometer reads 40 mph as soon as I turn my ignition switch. It reads incredibly high on the road approximately 40 mph high. Did a search but didn't find anything. Any help is greatly appreciated.
John

 

Check and clean the connection at the vss on the trans or transfercase.

 

checked the connection and it looked good. The speedo was still registering 40 mph with it disconnected.

 

Need some help here guys and gals. I did some wiring checks and I am registering 4.5 volts comming to the speedometer from the VSS input wire without the vehicle moving once I turn the ignition switch on. Can the VSS generate voltage without the vehicle moving if its broken? I dont see how this is possible. Does any have any ideas. Like I posted above the speedo registers about 30 to 40 mph once I turn the ignition switch.

HELP!!!

 

I would bet the speedo is bad or a shorted wire somewhere.

 

When I installed my NV4500HD I had the same problem. My speedo read high. I had my Dad drive at a set speed, say 40 mph and noted what speed my speedo indicated. I then went to my local speedometer shop and they built me an adapter that went on to the VSS to correct the difference - problem solved. My speedo is now within 1% of my actual speed - GPS confirmed.

Bob

 

Bob,
Had the same issue and did the same. Speedo worked great for a while but this is a different issue. Like I said the vehicle is NOT moving and the speedo reads 3 to 40 MPH.

Mopar Nut,
I am thinking the same but can't figure where 4.5 volts would be comming from. I could understand 12 but not 4.5. Do you know if the only voltage to the speedo from the VSS is the voltage generated by the VSS?

John

 

Sorry I dont have any advice but don't feel alone mine does the same thing. May read high, bounce around and then go to zero. when you figure it out let us all know.

 

roctoy

Sorry I miss read your post.

gcliburn

If you are running a G360 instead of an NV there is a different set of problems that cause your problem. I would suggest you do a search regarding the trans output shaft nut. If that does not work PM me and I will let you know about a TSB Dodge had out on your problem.

Bob