Nissan Repair: Emergency, electric switches, nissan truck

Question
We have a 1999 Nissan truck and my husband had to hit the brakes very hard and after that, the ABS light came on then the airbag light and it quit getting power and jerks very bad. The battery and alternator both check good but something keeps sucking the power out of the battery. We put his brothers in and started it then put it back in his brother’s truck and it sucked the life out of that battery too.
Have to have this fixed for work!!

Answer

Voltage draw test Hi Kathy, looks like there is a voltage draw in the '99 Nissan truck. Let's start from the battery, a healthy battery retains a voltage of 12.6V. If not, then it needs to be replaced. A hydrometer can show the bad cells if any. Now the alternator. The alternator needs to put out between 13-14 volts under load. This means with headlights, a/c and other accessories on. If not, the engine runs on battery power and eventually the motor will quit running. Also, when the voltage is very low, let's say 10 volts, some electronic components will cause their warning lights to come on! A battery that has 11 volts it may crank the motor but it will not start. If the alternator cannot charge the battery because either the alternator is bad or the battery is bad and it doesn't take the charge, you will see some lights coming on like a Christmas tree. If all these are ruled out because you already ran these tests, then we may have a voltage draw somewhere. This means that some accessory is "Stealing" battery juice when the car is asleep at night. Connect the test light as you can see on the image I drew. Disconnect the negative battery terminal and connect the clip of the test light on the cable, not the battery. With keys off the ignition, all the electric switches off and doors closed, touch the positive terminal with the tip of the test light. Light off, everything is ok. Light on, trouble. With the test light still connected start removing fuses one by one. When one of the fuses causes the light to go off when pulled out, then the problem is in the accessory in which the fuse corresponds. It could be a cigarette lighter even a dome light. Good luck!