Dodge Ram 2500 Cummins 2005,

Tachometer sometimes idles at 800rpm. Most of the time 1000rpm. running down the road always registers 2000rpm. When you get into it will not go by 2100rpm. Running at constant 35mph registers 1800 to 2000rpm. Sometimes drops to zero at idle. Sometimes at 60 mph 500rpm. Where lies the issue?

 

I *think* you can do a gauge/cluster test by holding the trip reset button, and turning the ignition on. (not start.) Should light up all the lights, and sweep all the gauges. See if the tach goes thru a full sweep.

 

Tach goes thru the full sweep. Have performed this test several times in the past. What is the next step cam sensor replacement? Now the amp gauge is stuck in the middle and not moving while on or off. Stayed in the same position while performing gauge/cluster test. Brand new issue.

 

Sounds like time for a new cluster...... see if that doesn't solve the problems.

 

Mine is doing the same thing. ...actually seems to register approx 500rpm less than actual. There are a number of youtube videos that show a repair process that entails re-soldering some pins on the back of the cluster. I am going to give it a try.

Good luck!