I have an interesting issue, maybe someone else has also experienced this issue. 2003 G35 coupe. I hop in car, I have dash lights, no sweat. I turn key and all power goes out. Disconnecting and reconnecting battery brings dash lights back on and turn key cranks car, no issues. It's a sporatic issue. I just did get the battery tested and they said the reserve health is bad. I'm wore l worried my computers going bad. The cars been tuned for a while and I do swap maps and use the antitheft map often.

Any help with this issue is greatly appreciated.