So I got to my car after work today and it was completely dead. Doors wouldn't even open with the intelligent key. Got a jump start and car worked fine. Drove home, no issues. Left it for about an hour then came back and it started fine. At this point I'm thinking 1 of 2. Either I left something on by mistake for 9 hours and it drained the battery OR there's an electrical leak somewhere. So I switched the car off, went to the battery, disconnected the negative terminal and hooked up a multimeter in series to read how many amps were being drawn. It showed around 0.8-0.9A!

My question is, is this normal? I know even when the car is off the analog clock is working and the receivers for ikey signal are also working, but is it normal to go up to 0.9A? I'm really hoping I don't have an electric leak or a short somewhere, but with all the custom wiring that I have done I wouldn't be surprised. Can someone with a multimeter be a champ and run a quick check for me

 

Could it be the vent control valve? Early g37 models have this issue. I too had this issue and got the VCV replaced under warranty and a free new battery from the dealership.

 

I see, I may as well just disconnect it then because I believe it is controlled by the OEM ECU which is non-existent in my case.

 

sam i had a similar issue with my car here in Canada... battery dies after awhile! , changed the battery twice and then found there is a problem with the alternator!

it chargers the car when it's running but when it's parked it drains the battery!, i changed it and problem was solved!

 

The alternator drains your battery when the car's not running??? How'd you come to that conclusion? How is that even possible?

 

^^^lol Jeremy.

 

i swear! that's what the mechanic said!...paid around $500 to change it and then problem was solved!

not sure how but he said he checked the battery when the car is off and he saw the battery is slowly getting drained!!...more than it should! and the alternator was the problem! even though it charges the battery fine when the car is running!

 

Wow....I seriously can't tell if the above is serious or not.

 

i can tell you myself....i am serious!!

i'm just telling you my experience and what i faced to help the OP, take it or leave it for all i care!

 

I can see this happening if the alternator has some sort of internal short that grounds out B+. The wiring within the stator or armature would provide some resistance vs a direct short, some current draw would be present.

Sam, I think it's easy enough to test by just disconnecting the connection at the B+ terminal on the alternator (thickest gauge wire going to the alternator). Be careful not to ground it, else you'll see sparks and further bad things may happen. With the car off, do your current draw test again. If the draw is reduced, you may have found the issue.

 

Thanks for your feedback fella's. It is indeed abnormal for an alternator to draw power but from what I read, a busted diode inside it can actually cause it to draw power when the vehicle is off. Will have to test it out, If it passes my test I will tackle the Vent Control afterwards.

 

Unfortunately, he is probably very right. Dishonest mechanics will tell you anything to make a buck. I took my Accord to a local all in one shop for some new tires - they had the best price - and the shop manager told me that my brakes were "dangerously worn" and they needed to replace them right then and there .... for $600.00!! Knowing that I had just done my front brakes 6 months prior, I took it to another shop and was told they were just dirty and they cleaned them for free. AND.... the shop tech told me that my lug nuts were dangerously loose so they torqued them to spec. Hmmm wonder how that happened???
Anyway, I drove my accord on the same brakes for another 25k miles before I sold it to get my G.

The moral of the story.... if it sounds fishy, get a second opinion.

G37sam, My 09 had similar issues and I took it to my local Infiniti dealer and was told that it was an issue with the BCM/VCV valve/Battery and all were replaced under warranty in regards to a TSB.

David