Car keeps dying!!!

[sp98gst]

I have a completely stock automatic 4g63t, when I first bought the car, the battery and the alternator were bad. I've replaced those and it's been a few months now. I checked the alternator and it turned out bad and replaced it just yesterday and it ran good throughout the whole day, but now it is still doing the same thing. The battery has no corrosion and the terminals are new, alternator and belt are new as well. My CEL light is currently on for both of my 02 sensors, I'm thinking THAT might be an issue but I'm just unsure at this point.

The car will start up fine, lights bright and all, but while driving, at some points the lights get dimmer and eventually die. When jumping the car, I let it sit at 2K RPM but once I switch it into drive the car immediately loses power and eventually dies.

 

[explicitgst]

Replace your front o2 sensor.

It should fix the problem, have you checked your MAF, vacuum lines?

 

[sp98gst]

Yeah, I've checked for anything out of the ordinary in the engine bay. Nothing else seems wrong. I will see if I can fix the sensor and return the results....

 

[STLskater92]

Start with what you know is wrong. No point in looking for a problem and ignoring the one you know is there. O2's then bring more info to this thread if the problem persists. And be careful when buying alternators for these cars, I spent over 50 hours workin on electrical stuff after a new alternator didnt fix the problem. Put a different one on, wala!!!!! Cars runnin like a champ But for sure, fix the O2 sensors before you mess with anything else.

 

[sp98gst]

Changed out the O2 Sensor, but the car is still doing the same thing.

 

[GST with PSI]

Do not change any more components. Just do a simple voltage output test on the alternator to start. Here's what you need:

-Volt meter (set it to DCV) the symbol looks like the attached picture below:

Start the car. Make sure all accessories are off. While the car is running put the black lead on the negative battery post. Put the Red lead of the meter on the B terminal on the alternator. This will the the largest wire hooked to the alternator, probably red in color but it varies. If you can't find or reach the B terminal, just put the red lead on the positive battery post.

Once you have both leads touching, take a voltage reading. It will probably be around 13 volts +/- a few tenths of a volt. Have a helper increase the RPM to about 2500, or just grab the throttle and do it yourself from under the hood. At around operating temp (140 degrees) the voltage should increase from anywhere between 13.4V-14.6V.

You are looking for a change in the voltage output from the alternator caused by increased engine RPM. Start with this before you go changing O2 sensors and unrelated components. If you see everything as I just said above, let me know and I can help you diagnose the charging system from here. If not then you likely have another problem related to this system. Perform this test and post your results. Good luck.

 

[GST with PSI]

Here's a pic of where the B terminal on the alternator is (In Red). Pull off the little plastic cap and touch the stud with your positive meter lead.

 

[laser5spdturbo]

Check the battery voltage again . An alternator is designed to maintain the charge on the battery . The battery maybe died again .

 

[rlacasse1]

Check your alternator fuse as well.

It just sounds like your alternators not chargin the battery and that is why your lights go dim after a while.

 

[sp98gst]

Yeah, I was able to get it to Autozone and checked the voltage, was getting about 11-12 on the meter. Turned out it was the fuse. Bought a new fuse, put it in and had them retest, got 13.46 on the meter.