I have a 2005 G35 Coupe 5AT with 72000 miles. It as been running fine until today I stopped at the store. When I got back into my car it would not start. Engine will not even try to turn over. Then I notice my windows won't roll down and my power seats wont' work. The radio works as well as all dash lights etc though. I tried getting a jump, resetting the ecu and nothing worked. At one point it did crank (after an hour of trying different things, I put my seat belt on and it cranked but I could not replicate this experience, coincidence I suppose) but when I tried to pull out it was bogged down so bad I could not safely leave the parking lot. I killed the car and the previous symptoms started again. I had to get it towed. This is the craziest thing I have ever seen. Can anyone help?

Summary: Car will not crank (or turn over at all). Some electronics work (dash lights, radio). Some electronics do not work (power locks, power windows, power seats).

Fun fact: Windshield wipers do not work but wiper fluid will still squirt out if button is pressed..

SOLVED: This ended up being a poor power connection to the upper fuse box. I replaced the terminal and plugged it back in and everything works perfect now. Hopefully this will help someone in the future,

 

I have seen batteries with busted cells that wont respond to jumping or anything. swap it with a known good battery from a another car to be sure.

 

Thanks I will try that. The battery is still under warranty since it is only 3 months old so I will probably just exchange it and see if that helps.

 

Battery tested fine at Auto zone and I put a known working battery on to see if it would help but the symptoms remain the same. What else could it be?

 

because you are describing random electrical faults, the next step would be to inspect and clean all ground connections. be sure to inspect all fuses as well. the FSM will show you the locations of all the ground connections on your car http://www.nicoclub.com/FSM/. this is correct procedure unless there is some well known electrical fault or TSB regarding the situation you are in.

 

check ur ignition switch relay, its by the battery

 

SOLVED: This ended up being a poor power connection to the upper fuse box. I replaced the terminal and plugged it back in and everything works perfect now. Hopefully this will help someone in the future,