I really can’t believe this actually happened to me after having boosted cars countless times in my life, but while attempting to boost a cold dead battery on my 2011 G37x (parked outside for 7 days in -30C temps), my co-worker incorrectly reversed the polarity of booster cable leads when he connected to his car’s battery!

After the leads were applied in reverse, and while totally unaware what had happened, my Infiniti car lights came on and the horn panic alarm triggered. I got the horn to stop sounding by pushing the door lock / unlock buttons on my key fob, but when I went to press the Infiniti start button, the gauges were totally dark and the start button was unresponsive.

After looking around, I discovered (in total amazement and horror) that the booster cables were reversed at the booster battery. Clearly, my co-worker didn’t intend to do this, so I did my best not to make a big deal about it.

After correcting the booster cable leads, when I went to see if my Infiniti would now start, I found the two ‘key fob not detected’ icons on the Infiniti gauges were lit. Of course, the car starter was unresponsive. I tried putting the key fob in the slot, but this didn’t change anything. My Infiniti also an aftermarket VIPER 5501 remote starter and this may also be involved given its tied into the car's starter.

Any thoughts? It’s as if the car starter is locked out, although I’m not sure whether the Infiniti and/or VIPER has an immobilizer function? I’m also wondering if a fusible link blew open, or, if I now have a problem with the ECU, etc!!!

I plan to disconnect the positive lead on my Infiniti battery in the hope that this may reset the ECU and maybe the VIPER. I also saw what looks like a set of fusible links between the main wiring harness and where it connects to the positive side of the battery, but I haven't yet looked in the G service manual.The VIPER remote starter does have an ‘Emergency Override’ that I can use to bypass the (optional) Failsafe Starter Kill function, but I don’t know think this feature is even set up on my VIPER remote start. Another possibility if that the VIPER module is 'fried' or a fuse blown open.

Any thoughts on anything I can try before towing the car to the dealer? To make matters worse, there are so many cars in the city with a dead battery that the towing companies may not be able to tow my Infiniti for a few days!

 

Tomorrow I’ll start by checking the fusible links.

 

not a great idea to use jumper cables on modern cars anyway ... voltage spikes can damage the electronics (computers everywhere!)

a good rechargeable jump-pack can boost many times on 1 charge, no need to get another car within cable length, etc.

i keep one in each car.

 

Thanks Landshark.

Before using the booster cables, we actually tried using a jump-pack, but it really didn't come close to having enough capacity (cranking amps) to start my G37x that had been sitting in temps ranging from -25F to -30F for over a week. Not only was the battery dead and frozen, the engine oil and transmission oil were quite viscous during the initial cold start.

Robert

 

So, I removed and replaced the fusible link that is connected between the main wiring harnesses and the positive side of the battery. When I removed it, I immediately saw the 140 Amp link was blown open as suspected.

While this finding was encouraging, and addressing this was the obvious first step, it however didn’t preclude possible additional damage being done to sensitive electronics during the time it took for the 140A fuse link to melt open. After replacing the fusible link, the car battery didn’t have enough charge to start the car which was moaning & groaning! So, I hooked up a battery charger and waited about 4 hours. While the it took repeated attempts, the car eventually fired up!

At this point, my G appears fully operational and the only remaining issue is a non functional audio system. The radio receiver works (can switch between AM / FM channels), as does the hard drive (can select my stored CDs), but there’s no audio regardless of the volume setting. I suspect either the fuse on the amplifier is blown or the amp itself is blown. Thus, at the moment I have no audio including Bluetooth hands free mobile phone, etc.

I’ll troubleshoot this issue next, but at least I have a working car. Fortunately the Engine Control Module (ECM) survived. I feared it might be toasted and I’d be looking at towing my G to the dealership to replace the ECM.

Robert

 

Glad the car is at least driveable. Time to invest in some smart cables...

 

a lot of those smaller ones (size of a thick smartphone) are ok for 4-cylinder engines, but you want something more substantial for larger engines. i have a small one for my wife's 4 banger, but the one i got for my G37 is the size of a brick.

 

I'm most delighted to report that all problems caused by reversing the polarity of the booster cables while jump starting my frozen G37x with a dead battery are now fully resolved. In the end this is what I did:

1) Replaced the fusible link due to the 140A link being blown open (CDN$36); this corrected a number of things, the most obvious being that my key fob was now recognized and corrected the previous telltale symptom where the only thing displayed on the gauges cluster was the two illuminated icons indicating 'key fob not found'.

2) Replaced the two 15A fuses for the Bose amplifier, fuse # 5 and #8, that were blown open (CDN$3). The fuses are located in the fuse panel behind the kick plate and to the left of the parking brake foot pedal. After addressing this, audio / sound was restored for the radio, hard drive CD collection, navigation, and blue tooth audio. Can't drive a G without tunes!

3) Replaced the two 15A fuses for the headlights, fuse # 56 and #56, that were blown open (CDN$3). The fuses are located in the main fuse box located in the engine compartment to the left (passenger side) of the battery. This required removing the battery cover & shroud, along with the cowling at the bottom of the windshield on the passenger side of the engine compartment. After addressing this, the headlamps now work again!

While in the end this unfortunate mistake only cost me CDN$42 and a few hours of my time, the hassle and cost could have been significantly more. I actually worked as a journeyman industrial electrician when I was younger and I'm still very fastidious. This is the first time I didn't supervise and inspect the application of booster cables to any vehicle I've had to have boosted. It goes without saying it won't happen again in my remaining lifetime!

Robert

 

You are very lucky. I've heard of such incidents resulting in fried ecu's, bcm's, and other $$$$$ parts.

Never entrust your neighbor to do a jump start properly

 

 

Jumper cables are a thing in the dinosaur age . They belong in the garbage can. Any decent portable jump starter should be able to start a G37, even with a completely dead battery, with ease.

 

Problem is they don't work anywhere near as well where it's cold so booster cables are an absolute necessity living here.

 

 

Last winter before before I replaced my battery I used a similar one to that to try and start my car when it was -30. It couldn't do it, booster cables being attached for 10 seconds allowed it to start.

 

Thank you Robert!! I signed up to this site to personally thank you for this info!!

After 5 years, this info is still useful and was exactly what I needed!

In Nov2023, The battery died before I was storing the car. I made same booster cable mistake but only affected the audio in my g37s 2010. i did check fuses on driver side AND they looked ok.

I took it out of storage in April 2024 and decided to buy a used amp and still no sound! I was really feeling in the dumps and didn’t know what else it could be !!

After reading your post this evening, I performed a continuity check on the fuses and they were dead!

So off I went to CT before they closed and got my self a set of 15A fuses, installed them in parking lot and then …. SOUND came out of speakers 😁

Lesson for me is don’t judge a fuse on how it looks! Always test it to be sure !

Again thank you for sharing this.

Joe