Disabling Smart Alternator on 2019 Sentra ?
- Thread starter SwampSurvivor
- Start date
The first step is to see if you have a draw. If there is no draw when asleep, then you can move on to things like the battery, or alternator - which is best to just monitor while driving.
If you do have a draw - then the next step is to find it (which I agree can be trying) but you can at the fuse box as suggested. You will need a probe with a long, thin lead. A small alligator clamp lead with a long stiff wire - like paperclip size, is usually the ticket.
What is your current draw at full rest? It would need to be pretty high to kill a battery while at work.
That's what is weird. The last time it had a dead battery at work, I drove it there with it charging at 14V the whole way. Then 5 hours later , it was dead. This is a new Napa Legend battery. I'll clean the terminals again, there's some corrosion forming. Only thing that makes sense if it was a battery issue is the battery isn't getting voltage because of the corrosion and the car is just running on the alternator?
I ran the original battery from this car in another vehicle and swapped it to my 4 wheeler to run the plow. It's working great still.
So when this battery went dead - what were the symptoms? Did the engine not turn over at all, or too slow? How did you correct the problem - did the car start with a jump start?
You would have to have a pretty great current draw to drain a charged battery in 5 hours.
The two times I measured it was at 10v on the battery posts directly. The doors would lock / unlock, key would turn on and fuel pump would prime but it would just click the starter relay once and then unlock the doors.
With the exception of one time (a time I didn't measure), it starts immediately with a jump start / booster pack. When it happened sunday I was pretty mad and in a hurry so I just hooked the jumpers up from the Marquis, hopped in and hit the starter button and it fired right up.
My van shows battery voltage, controller voltage (was slightly different vs battery voltage in my case), commanded duty cycle of the alternator, and alternator output. See if it’s commanding anything out of the alternator when the voltage dips. If it is, alternators likely bad.I do have a BT OBDII scanner that could do it. I'm wondering if that's seeing different voltage than what I'm seeing directly on the battery? I'm sure that could cause issues. I have used a multimeter connected directly to the battery while driving and it's definitely doing smart "dumb" alternator things.
As I learned in the past, my Jeep will run 90 minutes with no alternator
Edit - nvm saw your other post
My 13' CRV does the same thing. Read somewhere to just drive with the lights on and will charge at 14 volts. I just plug it to a tender everyday. I'm not changing bulbs every few months !!....Ran fused 16 gauge wiring from the battery to outside the grill with a plug end. Just plug it in at night.
