Infiniti G35--Electrical, requires jumpstart although battery is new

Intermittently, cannot relate to any pattern. Not that often, but a huge hassle when it happens.

What? Well, my car is completely dead. Smart key will not open door, so have to use the mechanical key to open car and open hood. Have to jumpstart car.

Car then starts normally for a few weeks until problem occurs again. Lather, rinse, repeat.

Battery is about 9 months old (replaced it when the car first did this–only owned it since November 2014). Smart key has brand new battery.

Have checked all fuses and relays that I can (a couple are enclosed in plastic boxes that I cannot figure out how to open). Have checked alternator, and it’s pumping out about 1400 amps.

Any idea what is the matter?

I think you have a bad connection somewhere. Rusted or corroded main battery or ground cables or connections. Check and clean all ground and positive connections and carefully inspect the cables themselves for hidden problems. If there is no power anywhere, that eliminates most everything except the main power source and cables. I suspect jumping the battery provides a better connection momentarily that clears a path for a while. Might be as simple as the connections on the battery. I used to replace the side posts on my batteries once a year and clean and neutralize the build-up just as a matter of maintenance.

Bing, are you saying I have a loose connection!? (…said jokingly)

I will go check on that now. Thanks for your analysis and recommendations.

Could not find anything, upon 15 minutes’ inspection.

Anyone else?

you have to unbolt the connections, remove them, and clean any corrosion.

I doubt the alternator is outputting that much current. Perhaps 140 amps.

It’s also possible the cables are corroded internally.

How old is this car? mileage?

Also clean engine and chassis grounds. Check alternator connections and repeat connector on it.

You may have a light that comes on randomly due to a failing/dirty switch. If you have them, take out the glove box and trunk light and see if the problem goes away. They may be turning on and draining your battery.

As said above, dirty connections are not always visible until you take the cables apart. On a 2014, I would be surprised they could be corroded already, unless the previous owner had an adventure with some water, which could cause all manner of trouble.

It’s actually a 2007. When I purchased it last November, it looked almost flawless as far as headlamp lenses not faded, paint like-new, and under the hood like a brand-new car. So maybe it was a salvage, although the title came back clean (actually, not entirely sure I checked it…got it through AAA Car Buying, which I figured was safe). The bank would have balked, though, wouldn’t they have, if it were a salvage title? Because it was an S model, and low mileage at 78,000 miles, it was at the high end of the price range but the bank signed on.

SteveCBT, I will try taking out the trunk light and glove box light.

I did a Google on “wiring diagram for Infiniti G35”, and it seems there is a wiring diagram for most everything. So eventually I may rely on those diagrams. ALSO: A neighbor is going to get his jack stands out of storage next week, so I can get it up and look under it.


You may have an intermittant drain, glove or trunk light might be on, brake light switch may be sticking, so brake lights kill the battery. Make sure everything is off when you exit the car, dome lights radio etc. That is where I would start.

If this problem only occurs on a first start of the morning, I tend to concur with posts above suggesting a phantom current drain condition occurring. I’d start w/the ideas posted above.

If that doesn’t work, diagnosing what’s causing it can be difficult. What can happen, when you turn the key to off and lock and door and leave it sitting for the night, the computer is still awake. And the computer is monitoring stuff to see if something needs to be done. Stuff like the doors. If it thinks a door is being opened, then the computer will turn on, which draws a lot of current. And something like the wind blowing against the door could make it think that, if the door switch sensor was faulty or out of adjustment. Likewise with the alarm sensors. This should be in particular considered a suspect if this car has any kind of aftermarket alarm system installed, or aftermarket audio system.

Equipment exists which could be hooked up to the electrical system and it would record the amount of battery current drain vs time. You might need to have that done, then at least you’d know if the current was spiking in the middle of the night or not.

dome lights would be my guess also, as I had one cause an intermittent battery drain problem in a Jetta. But watching for it to go out is complicated, as there is a circuit that turns it off a minute or so after you exit the car.

From that article it looks like the radio may be the common culprit. Pull the radio fuse at night and see what happens. If that’s it, put the relay in.