2003 G 35 Sedan, this week I have experienced a problem when starting in cold weather, in the teens and low 20's. I am in Northern Ohio. When I turn the key to start nothing happens, no starter clicking, acts like automatic transmission not in neutral or park. I had it jumped by AAA and it did the same thing through 5 or 6 attempts. Finally after that many attempts I tried again, and on the 2nd try this time it fired up normally.
I have cleaned the terminals, and posts completely. Put my 6 amp charger on and it didn't respond just pegged on the 0 amps, denoting no charge needed. This happened 3 times in the past 4 days.
Is it possible that I have a starter relay problem? If so if I can replace it myself, where will I find it and how difficult is it to replace?
Is this a problem that can be diagnosed by using a scanner? Is it recommended to take it to a mechanic or dealer? I look forward to all comments.

 

Your car may have a bad clutch safety switch. There is a switch that is depressed when the clutch pedal is pressed to start the car. They sometimes go bad. The switch on my 04 6mt coupe is bad. All of the electrical systems will work but the car won't try to turn over. I had to pump the clutch pedal with the ignition key turned on to get the car to start.

 

is this a manual?

 

My car had a similiar problem starting when the outside temperature turn below 32 degrees. It would take 1 or 2 seconds to start. How old is your battery?