I have searched and still nothing. My car has been dying like the lights dimming and stereo shutting off and then boom car dead. IDK what it is i was told my alternator so i took it out and got it teasted and it passed the test. Does it vary if the alternator has been running or not for it to pass ? Any ideas?
Can involve something to do with fuel leak somewhere, I would start with that or wiring issue
Some times the alternator will pass the test but it will still be bad. To see if its the alternator and not the battery,start the car and pull the negative side cable off the battery and see if the car dies. If it dies,the alternator is dead,if it don’t die its the battery. Also check the grounds as well,there’s one running from the transmission and one on the valve cover,you need both or you wont get the full charge the battery needs.
What dose dimming lights and dieing radio/power have to do with fuel?
OK cool i was thinking to do that test, but i heard it might damage your car. Although the battery is brand new i just bought it becuase i thought i had a battery issue, and turns out I was wrong.
Yes it could damage your car.
Some people tell you that you can check your alternator by disconnecting it from the battery to see if the alternator can produce enough current to keep the engine running. BAD IDEA! Disconnecting the battery will subject the voltage regulator (and computer and audio equipment…) to significant voltage spikes which may cause an otherwise good alternator to fail. Even if there were no damaging spikes, this test would not indicate whether or not the alternator was good because the engine will easily run with a weak or failing alternator.
He didnt say if he had trouble starting it which would be something with the charge system, just throwing ideas out there till he comes back with more info.
So how can i really get down to what the problem is? I took out my subs amp and disconnected almost every aftermarket electrical thing i could think of and still dont know what cause the car to just loose power and have the battery light on till it dies.
If you have access to a voltmeter go out and measure the voltage coming out of the alternator it sounds like its your alternator though you. Voltage should be at around 13.5v to 14.4v at idle at least pretty close to 13.5v.
[QUOTE=Mexicanpollo;2196928]So how can i really get down to what the problem is? I took out my subs amp and disconnected almost every aftermarket electrical thing i could think of and still dont know what cause the car to just loose power and have the battery light on till it dies.[/QUOTE]You need to test the alt. while it’s in the car, under load.
It could be as simple as no power on exciter lead to the alt., it would test as OK on a bench, but have no output when in the car, most batt./alt. shops will do a load test on the charging system for free,it only takes few min., or you can test it yourself with a multimeter, should be 12.5V engine not running, 12.5V engine running. up tp 14.5V with RPM up. 94
[quote=fcm;2197038]you need to test the alt. While it’s in the car, under load.
It could be as simple as no power on exciter lead to the alt., it would test as ok on a bench, but have no output when in the car, most batt./alt. Shops will do a load test on the charging system for free,it only takes few min., or you can test it yourself with a multimeter, should be 12.5v engine not running, 12.5v engine running. Up tp 14.5v with rpm up. 94[/quote]
yepp he sums it up…
thanks for the help!
Im glad i came across this thread. I hope im not thread jacking. But I just finished swapping a b18b into my da. And now im having trouble with what seems to be the alternator. Before the swap the battery light came on randomly. But now the light stays on when the car is under 2500 rpm. When above that the battery light turns off. Now im thinking that the alternator is not charging and that the car is only running off the battery. If i drive the car a while day the battery dies. I have noticed that there js one random cable. Looks like a ground. It bolts to the side of the strut tower and just kinda hangs. Haha. Autozone guy told me the voltage regulator is going out. But seeing that somebody mentioned something about a ground on the transmission im now thinking i should try to hook that cable up. What do u guys think?
OP. How old is your battery? Might just be time for a new one if its getting old
A picture of this wire your talking about would help. The voltage regulator is built into the alternator and can go bad. It most cases people just replace the alternator.
I would find out where the other end of that cable goes before you just hook it up.
Does your belt squeek at all. My only thought would be a sliping belt