I have a 2005 Infiniti FX35 When driving I saw fuel, miles, temp needles at zero. Should I assume the Instrument Cluster must be replaced? Or should I test or reset it? I believe I have the tools to replace it but I’m concerned about how to reset to the correct mileage and I have no idea where the miles were set. I haven’t found anything on that.
I believe I need to disconnect the battery but is it necessary to disconnect the airbag?
also is the instrument cluster a part that I could replace with a Nissan part? I would appreciate any information for my problem, thank you!

 

I'd check it's fuses first, it's powered by Fuse Block - J/B which is the cabin fuse block behind the access panel in the driver footwell. Here is the instrument cluster power schematic followed by a layout of FB-J/B for the fuse locations. In the first schematic you can see it gets power from fuse slots 19, 12, 10, and 11. In the second diagram I drew arrows showing which ones you should inspect first.

Does everything else in the vehicle work properly?

 

Also check fuse 14, I should have scrolled to the next page of the power diagram.

 

Thank you for everything you wrote! Although I have another issue. The car is completely dead. I drove it about 12 hours before I was aware. I had taken it to an auto store to see about the fuses in relation to the instrument cluster being out The store clerk brought a piece of equipment out and tested the battery, alternator & something else. He said everything was in great shape. Could I have damaged the car from driving without the instrument cluster? I cleaned the cables and will test it again.

 

Doubtful you damaged anything unless the car was overheating and you didn't know.

The positive battery terminal has a bunch of fuses on it called the "fusible link", I would inspect them as well to see if any are obviously blown/burned/etc. One of them supplies the power to FB-J/B.

 

Later today Triple A replaced my battery. It was just out of warranty. It fixed the Instrument Cluster!🥳 How did that happen? Can I feel good about that? It seems strange my battery would have no charge. Of course the instrument cluster is likely not a high demand repair either. I really appreciate your advice & input thank you!

 

Sounds like the technician that initially "tested the battery" didn't know how to use the equipment. Typically you will do an alternator output test which is leaving the battery connected with the engine running, then turning the load bank heater ON (on the test cart) while you watch current and voltage.

Next you turn the car off, disconnect the battery cables and then load bank JUST THE BATTERY while looking for voltage drop (sometimes shops leave the battery connected but it's always best to isolate the battery for a good clean test).

Sounds like he never did the second part of the test, the alternator on these cars is pretty darned good since it's built to run things like the seat heaters.

 

I know electrical problems are a nightmare as well as expensive. I will consider faulty intermittent battery tricks first next time! I appreciate the time you took to help me out. Now that I have a better idea of where what and how I’m going to check some of the fuses anyway like the back cigar lighter and door locks maybe I can get those working! Thank you!