battery/alternator question

[dnhieu]

okay. i just bought a new talon and its having a starting issue. when i bought the car it had a bad power steering leak which leaked all over the alternator. i assumed that this is the problem and fixed the leak and replaced the alternator with a spair i had around the house (looks brand new). well i throw the battery back in and it doesnt want to start. so i go to jump it and it starts up but when i take the cables off it dies right away. i take the battery to get tested/charged and its not holding a charge.

my question is, is the battery bad or is this alternator i just put on bad? im pretty sure its the battery but i would like to ask everyone else before i go waste money on a optima red top.

thanks in advance
david-

 

[majik2k5]

Chances are it's the battery. Had a problem similar to that.

 

[dnhieu]

alright cool, thanks

 

[importboost]

sounds like both to me...if the car dies right after you take the cables off its running on the alt. the alt charges the battery. thus taking the battery almost completely out of the new circuit its made. so take that alt you had sittin around back off and go get it tested. never hurts to double check

 

[travislaw]

You could always take both to Autozone and they can test it for free so you can be sure what you need to buy.

 

[dnhieu]

damn that sucks. i was thinking that the battery was so dead that the alternator couldnt keep up. what do you guys think? i had the battery tested and they said it was no good.

thanks
david

 

[importboost]

i already told you to go ahead and take the alternator off and get it tested...thats what i think

 

[dnhieu]

i already told you to go ahead and take the alternator off and get it tested...thats what i think

i was wonding if what people thought of my idea that the alternator couldnt keep the motor running because the battery was dead. not what you thought about the problem in genearl because i had already asked that. sorry for the confusion.

 

[majik2k5]

If your battery is no good, you're gonna have to get a new one anyways, so I would get a new battery, get the car running, and drive to the closest Advance Auto Parts or AutoZone and have them test it like said above.

P.S.... clear out some of your private messages, haha.

 

[dnhieu]

If your battery is no good, you're gonna have to get a new one anyways, so I would get a new battery, get the car running, and drive to the closest Advance Auto Parts or AutoZone and have them test it like said above.

P.S.... clear out some of your private messages, haha.

sounds like a good plan to me.

 

[importboost]

i was wonding if what people thought of my idea that the alternator couldnt keep the motor running because the battery was dead. not what you thought about the problem in genearl because i had already asked that. sorry for the confusion.

tis all good man. well i guess if you go get a new batt and it still doesnt start. you will know you have to go back to advance

 

[dnhieu]

their is only one wire that runs from the alternator to the battery correct? im trying to figure out other possible problems i can come across. another thing i found out was that the alternator fuse could have blown. ill check it tomorrow if its not raining.

david-

 

[importboost]

their is only one wire that runs from the alternator to the battery correct? im trying to figure out other possible problems i can come across. another thing i found out was that the alternator fuse could have blown. ill check it tomorrow if its not raining.

david-

only one to the battery...but double check your ground wire. bad ground = bad connection = 1 good reason alt isnt working. o yeah and check that fuse.

 

[dnhieu]

the ground wire on the battery correct? or is their a ground on the alternator?

thanks
david-

 

[steve]

their is only one wire that runs from the alternator to the battery correct? another thing i found out was that the alternator fuse could have blown.

Just that one wire that runs through the alternator fuse. The Alternator is grounded via the bracket it's mounted to. The other two wires to the plug on the 1G alternator are for the field. The main B+ wire is the one that goes from the battery, to the alternator fuse, to the stud on the back of the alternator.

Steve

 

[dnhieu]

Thanks. Ill post back when i get some more information.

 

[dnhieu]

okay, i just checked the alternator fuse and its blown. Its an 80a fuse correct? what kind of problems am i looking into if i get another one and they keep blowing?

thanks
david-

 

[talonfromtenn]

If you stick the new fuse in, and it pops instantly, or as soon as you turn the key, chances are that you have a short. I'm not saying that you do, but it's a good possibilty. I wouldn't go pullin' off the cables from the battery to test your alternator though. It can cause a voltage spike that could fry the computer, or a very expensive sensor.

 

[dnhieu]

I wouldn't go pullin' off the cables from the battery to test your alternator

what do you mean by this? im confused on how you test the alternator in this fashion?

 

[importboost]

just go to mitsu and get the fuse...its like 8bucks. if it pops again, check your ground for the circuit. something is shorting. i have no idea what talonfromtenn is talkin bout, the only way i know it can do that is if you jump start the battery with another car and the voltage regulator isnt working properly. then you can fry the ecu in the jump car.

 

[steve]

i have no idea what talonfromtenn is talkin bout

I know exactly what he's talking about.

Some people think that it is ok to test your alternator by starting the car and then pulling the battery cable from the positive terminal, saying that if the car remains running that the alternator is good.

Like he said, this is a bad idea because the alternator can load dump and spike the whole electrical system with >100v and even if it doesn't, the battery filters the alternator output and the AC ripple on the output will again flow through the whole electrical system. Both of these can damage the ECU and other electronics in the car.

Steve

 

[baracuda645]

I believe you need a 100 apm fuse, i had a similar problem with mine. It turned out to be my alternator, I had a dead short in it (short within the alt itself) . It would drain the power out of my battery as well. My recommendation would be to purchase a new alt and battery if all else fails. I havent had any problem since.

 

[dnhieu]

ill post a pic of the fuse that is busted tomorrow morning to make sure its the alternator fuse. i put in a good alternator that i pulled off a running car before it snaped a timing belt. it looks brand new so im assuming its good. i ordered a optima red top battery also. ill keep everyone informed.

thanks for all the help
david-

 

[baracuda645]

When i checked mine it would pop a new fuse as soon as you turned the key over. Took me a couple of hours to figure out what had happend, i'd never seen it before. My alt had 96000 miles on it when it went. The fuse should be the first or second in your fuse box. You need to unbolt it to get it out.

Ken

 

[importboost]

I know exactly what he's talking about.

Some people think that it is ok to test your alternator by starting the car and then pulling the battery cable from the positive terminal, saying that if the car remains running that the alternator is good.

Like he said, this is a bad idea because the alternator can load dump and spike the whole electrical system with >100v and even if it doesn't, the battery filters the alternator output and the AC ripple on the output will again flow through the whole electrical system. Both of these can damage the ECU and other electronics in the car.

Steve

ah never heard that. thanks. i learned how alts worked doing something like that...but not in a car. volts read off the chart. volt meter couldnt read it.

the fuse is 100amps, like i said its 8 bucks at mitsu. its bolted into the fuse box on both sides and it looks like it has a nipple on it and its in a clear case.