I need some help bad, my car died on me for what seemed to be my alternator, because my battery went dead. I replaced my alternator as it was actually bad. but now I still have the same problem...
please help!!! alternator not charging battery
- Thread starter Black_Snake
- Start date
Might need some more details.
How long is it taking for it to go dead? Has either alternator been tested?
How long is it taking for it to go dead? Has either alternator been tested?
Your 20amp battery fuse is bad , when alternator goes bad it overloads the fuse . I just replaced alternator on my F150 today , still no charging after new one was put it then I changed the fuse and boom ... alternator started working . check owners manual for fuse number ,bad fuse was in the fuse box under the hood on my f150
Last edited:
I tested the old alternator and it was bad. So of course I bought a new alternator assuming that would fix the problem. Drove it to work and back and lights went dim, rpm gauge went out. after a total of 30 mins of driving. I checked my fuses, and they're all good. All my wires seem to be intact. also I have heard our alternators need battery power to run at all. Any truth to this?
What kind of alt did you buy? Auto zone reman? If so, they are junk.
Have you tested the new one? Sometimes they are bad right out of the box
Yea I got it tested when I bought it. It tested good.
Yes, there is truth to that.
My car was able to idle on the alternator. Never tried to drive it like that though. Just because you tested it when new does not mean it is good right now. Take a voltage tester to it. it should read 13.5-14.4. On a cold start first of the day it should be in the 14.2-14.4 range. Your battery should test in the 12.5 range after sitting over night.
Also, a bad battery will most times show 12.5 or so voltage but not hold under load.
You need to have both battery and alternator checked.
On the car charging system test would be best.
You need to have both battery and alternator checked.
On the car charging system test would be best.
Also double check your alternator connections, I replaced the alternator once and had the same issue, car went dead, I didn't have the alternator harness plugged in tight.
Break out the multimeter and check the megafuse for continuity. If it passes, then start the engine and test the alternator output. Either the alternator is not producing power, or the power isn't reaching the system/battery due to a blown megafuse.
Here's a picture of a megafuse, just to be clear:
Here's a picture of a megafuse, just to be clear:
Last edited:
Users who are viewing this thread
