I have read as many threads as I could find about tachometer problems. The only fix I have found is to replace the cluster. Someone else suggested replacing the crank shaft sensor, I tried this and it didn't fix the tach. Does anyone know if this is the only true fix, because this is terribly expensive. Cold temperature has something to do with the problem. When ever we have a strong cold front come through, my tach starts working, and works correctly for about 2 days. Anyways, I am getting 15-16 mpg at best and have noticed others are getting better, is there any correlation? I forgot to mention mine is a 5.7 hemi with around 117000 miles.

 

I've been told you can just replace the stepper motor on the tach, if you know someone or are good with electronics yourself. I have not got around to fixing mine yet.

 

You can do a guage check.
Press/hold the trip button while you turn the key to the ON position(just before crank, but dont start!) Then let go of the trip button and your guages should sweep one-by-one. If your tach guage failes to sweep, then it is bad and your cluster needs to be changed. A new cluster is not as much as you think they are but they do need to be set-up for your mileage and vin options.
You would go to the dealer, have them record your mileage and vin and then order you a new cluster(refurb actually). Once you get the cluster, you can install it yourself without any programming.
You might be able to find a place online but not sure how they do the mileage thing? Maybe an authorized garage letter stating actual mileage?? Anyways, I paid $300 from the dealer for my '08. I seen them online for $189 new/refurb not no ebay used stuff. Clusters need to be prgrammed to your vin options and once they are installed into a vehicle, they auto program themselves only once. So, a used cluster off ebay will not be programmed to your truck. just a forewarning.

 

Thanks guys for the replies. I have tried the guage check and my tach didn't move. What baffles me is ,if it is bad, why does it work sometimes? It is like it has a short. When it is working, there seems to be a significant weather change. I know electrical shorts do CRAZY things, but they can be fixed. Anyways, it will be a while before I can afford another cluster, so I will just live with it for now. Thanks again for the responses. Oh, I read somewhere else about the stepper motor, but never heard if it actually worked.

 

I am sure you found my thread about my 06' tach going haywire recently. Although oddly enough, since adding Techron to my fuel, the tach has been working fine since. Go figure.

In any event, seeing as my truck is an Automatic a tach is a luxury, not a neccessity. I can tell what my engine is doing by the sound and feel. You know when your over or under 2k RPM even without a tach. One day when i have $300 burning a hole in my pocket, ill replace the cluster, untill then? i don't even notice it when it does not work typically.

 

Hi, I recently bought an 06 Ram truck. I am having problems with tachometer my truck. At idle it will often read between 100 - 300 RPM but the engine is idling normal. Is there any updates for this issue. I have 5.9 Cummis and standard transmission.

 

This may work
http://www.cumminsforum.com/forum/3r...ch-issues.html