I just picked up a 94 2500 ctd, from a buddy of mine. He told me the speedometer did'nt work so he replaced the sensor on I believe he said the tranfer case, anyways it did'nt fix the problem. Sometimes while driving, say like 60, the meter will bounce up to 100, and might stay for awhile, or not. any ideas for a place for me to check? Thanks

 

Is the Brake/Abs light on?

You may wanna check the Speed Sensor. It is located on the top of the diff. of the rear axle. Mine was acting up so i replaced it and now its good to go.

 

I did'nt notice the brake/abs light on, will check for that tomorrow, the 4x4 light is on all the time though. I wonder what sensor he changed on the tranfer case was, I'm sure thats what he said.

 

I replaced the sensor on the rear axle, still no speedo

 

THe crank position senser CPS is on the block above the damper. It sends pulses to the PCM and without it you get no speedo, alt charging, MIL light, WIF light, etc. It is .050 inch above damper. Try checking the gap and make sure its working.

The CPS is probably working or you'd have other symptoms but just worth looking at. You may have a bad dash gage or wiring issues.

 

I'll check it out, thanks

 

thre reason you 4x4 light is on is pecause your front axle is locked that means you have a vacuum leak or no vacuum at all