Got a strange one for you smart folks!
 

Greetings! Proud new owner of a 2003 350z Touring with 60,460 miles on it. I've had the car for about 2 weeks and over the last 3 days I've noticed a strange occurrence. When listening to the radio, the subwoofer stops working and my oil pressure gauge maxes out. This happens at exactly the same time, and only occasionally. Otherwise the bass works like it should and my oil pressure reads where it should be when idling, driving and etc. Could there be a crossed connection somewhere? And if so, where would I begin to trace the problem to? Any help with this would be greatly appreciated, the occasional lack of bass doesn't bother me but I really don't like not being able to get a good reading on the oil pressure when this happens. Thanks! :)

Known issues....searching is your friend

So far I've been able to find the issues happening separately, which are both simple fixes, oil pressure sensor replace and whatnot. But the two occurring at the exact same time leads me to believe that there is a bad connection possibly? Something may not be grounded correctly?

i believe you answered yourself. Start with the battery, then the module under the battery etc, etc...
Does the voltage reading stay put when this happens ? Or just the oil pressure gauge.
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Might sound redundant, but does your Touring Z have the factory Head Unit or an aftermarket? It sounds like you have the original Bose Subwoofer installed, so I'm guessing you have the matching Bose head unit? IF an aftermarket head unit was installed or you have an aftermarket woofer, I would start by checking the wiring there. The OEM Bose systems are extremely picky/proprietary, any changes made to components of the system can cause weird/bad stuff to happen. I've heard of adapter kits made that allow the OEM Bose amps (PAC-ROEM) and such to work with an aftermarket unit, but I've never personally seen or used one.

If your new used Z is stock/unmolested, but is showing signs of rust in the engine bay or on interior bolts and such, I would definitely start checking ground connections. As stated by fflipski, check the battery ground, then the fuse box under/next to the battery and continue with interior grounds (fuse box on driver's side kick panel). There are various other ground connections scattered around the interior hiding under panels, checking them all would be a nightmare so try to focus on the most likely suspects. Get ahold of the Factory Service Manual or wiring diagrams and try to find the common denominators between the stereo and triple gauge pod in the center dash.
Good Luck!
-Icer

You're not alone. '03 Touring with 93,000 miles - been a trooper in the reliability dept. until a few recent events..

My Oil Pressure Gauge is Maxed, stuck there, has been for 'bout 1 month now. ( Clogged PCV Valve ? - also, small oil leak from ? - developed as of late when motor running )

My Big Bose Speaker has a mind of its own, only kicks in on rare occasions, then cuts out, has done this for some time now.
Have the Stock Head Unit, it also doesn't like playing CDs when below 40 degrees out and skips and cuts out too when playing CDs depending on road bumps that cause it.

Guess I should jiggle the battery cables and see what happens :dunno:

I don't wrench, all my tools rusted out when tool box was in my '72 Mach 1 in the early 80's... Rusted rear wheel wells caused wet trunk and rusted all the tools in there...
Gotz me no Metric tools either

The bass cut off is a known issue with the amp I believe....there is a how to on how to fix it on here