Power from the tach comes from the ECM located under the center of the dash. See attached picture.

Answered by Jacobandnickolas (expert)
57,475 answers provided

Thanks Jacobandnickolas! ECM, I'm guessing thats the electronic control module? Sounds expensive if I have to replace. I'll take apart the dash and see if connection is loose. Do you happen to have a diagram or step by step how to get to the ECM? I have the Oem service manual somewhere...

Thanks again.

Response from sumac0401
3 questions asked

You shouldn't have to remove the dash. Give a look and you should find it. As far as a diagram, my manual doesn't provide that. And yes, electronic control module. In addition, make sure all body grounds are attached and in good condition.

Let me know what you find.

Answered by Jacobandnickolas (expert)
57,475 answers provided

Thanks again, Jacobandnickolas. When I have time, I'll remove the instrument panel (should be just 2 screws and it will pop out) and see if the harness connector has voltage in the documented terminals listed in my Nissan Altima Service Manual. If not, I'll have to check to make sure the connection between the instrument panel and the ECM is secure. Hopefully I will not need to get a new Tachometer.

Response from sumac0401
3 questions asked

I hope it is something simple. Let me know what you find or if you have other questions.

Answered by Jacobandnickolas (expert)
57,475 answers provided