Electrical issue

[chubbytoo]

I have a 2018 Altima. The battery was changed about 3 months ago. The last one was so corroded the posts were loose. A few days the car wouldn’t start unless it was jumped. The battery tested good. I put it in reverse and the dash lights, the stereo, and the headlights all went out. The power steering went out too. Lasted for about 2 seconds. I figured it was the alternator. I took it out and Autozone tested it 3 times. It passed each time. The battery is fully charged and the alternator is alternatoring. I have driven it 300 miles without any problems but as soon as I turn it off it is dead. Can’t even lock the doors. There is a clicking coming from the fuse box under the hood. After a couple minutes the clicking stops and there is enough power to lock/unlock doors and even give dash lights but the car still won’t crank without a jump. I’m going nuts. What is the problem?

[VStar650CL]

If you're certain the battery is good, then plainly you have a cabling problem. If you changed the battery without changing the lugs, it's possible you simply have some green rock candy mountains hiding inside the old positive lug. Gen5 Altimas also have a 2-piece ground lug to allow the battery current sensor to be separate from the cable, but if the nut holding the cable to the lug comes loose it can create enough resistance to disable the car. Make sure that nut is tight. Lastly, the battery cards can sometimes fatigue and crack internally where they right-angle, which can cause the same sort of resistance on the power side. In addition, the cards also have a nut and stud arrangement where they attach to the lug, those can corrode in between the card and lug where the corrosion can't be seen without separating them.

[chubbytoo]

I took the battery out and inspected and cleaned everything I could. The battery fusible link on the positive side was super corroded and nasty looking. $55 to change that. I also ordered the battery current sensor for the negative side. After changing the positive side fuses, it worked. I didn’t have any of the problems as before. However, I’m not convinced that is the solution to the problem because I had also charged the battery overnight so it was completely full. If the problems start again after a week or so then I’ll change the negative side sensor. The OEM part is $500. I found it for $150 at Autozone and $45 on Amazon. I’ll post a follow up in a couple weeks. Hopefully, the positive fuse block was the problem.

[VStar650CL]

The sensor itself is never the problem, the "tongue" on the cable which passes through the sensor is what corrodes or gets loose. Don't waste money buying a sensor, it won't help anything.

[chubbytoo]

It’s been about a month and haven’t had any more issues. I didn’t change the negative side sensor. I returned it to Amazon. That’s for all the help and recommendations!!

[VStar650CL]