tach ques.

[Reaper26]

i recently changed my pcm, it was throwing codes and skipping bad, for a while now the tack kinda jumps on its own and doesnt respond the way it should. theres not always a change in the engine idle usually its just the needle dropping. theres a wire or two going to the throttle body that has a bad spot where sumthin chewed on it. could that cause my prob or could it be a sensor and if so which one?

 

[charonblk07]

I would start by replacing the bad wiring, soldering in a length of same gauge wire (22ga IIRC) into that harness would work, don't butt splice it since it's a voltage sensitive system. After that then you'll have a better idea if it's computer related.

 

[07MegaCabRam]

There seems to be some sort of common problem with these tachs because of the circuit board being tighten by the factory with too much pressure causing them to warp.

There are good videos on youtube if you search dodge ram tach fix.

This may or may not be what you are expriencing.. but seems to be an easy fix if your tach isn't responding correctly/low.