Dakota Tachometer reading incorrect

1994 Dakota 5.2 with 5 speed manual transmission

Tachometer seems to be reading at least double what the engine is actually RPMing at. Example: The engine is running about 2,000 rpm the tachometer is reading 4,000ish and then sometimes the tachometer is just acting all sorts of wacky bouncing around.

What is the way to go about diagnosing this kind of issue? Cluster? Some type of sensor? Thanks

Sorry, no help here, just commenting because I'm in the same boat.

I'm having issues with the tach in my '92 Dakota. What I've noticed with mine though is when it 'flat-lines' (doesn't read anything) it almost feels like the brakes are dragging, the truck looses its 'snap'. It's a subtle difference, but there is a difference.

I'm not sure how to diagnose it though. Yours might be easier being OBDII , but I don't know.

I've asked about the tach in my truck a few times, but no one seems to know how to diagnose it. A member here offered a known good tach to me and I swapped it in but no real difference was seen.

Same here with my 89 Dakota 3.9. Bouncy tach????

If you remove the instrument cluster, you'll see a little circuit board about 2" x 3" or so. it snaps off of the cluster. A lot of times you can actually see cracks or dimples around the larger solder joints on that board. Take your soldering iron and maybe just a small amount of new solder and re-flow those joints. Take care not to bridge any circuits with solder. Pop the board back onto the cluster and install it back into the truck. It should work much better.