Need to replace alternator?

[YelPro03]

My wife's '03 P5 just died. I mean she was driving and all of a sudden all the different lights on the dash come on, then radio stopped working, and then eventually the car just died. She calls AAA to get it towed back home and the tow truck driver said it is most likely the alternator. He tried to jump start it and the engine came back on but as soon as he disconnected the negative terminal the car dies right away. Tries again and the exact same thing happens. He said it's not the battery because even if the battery is bad and the alternator is still good, the alternator is still able to deliver electrical power to the car. But if the alternator is bad the car will only keep running until the power stored in the battery is used up. Makes sense to me. What do you think? Also, how much can I expect to get the alternator replaced so I'll know I'm got getting ripped off.

Thanks.

 

[bucksatan]

If the battery is really really bad the alternator might not be enough to keep the car going, as the circuit is basically broken by the dead battery. Make sure that the wires are properly hooked up to the battery, and the terminals are clean. I've had similar problems from loose or dirty contacts on the battery.

It sounds like the alternator is the problem, but you might as well check easy things like all the contacts, loose belts etc first as those are easy to fix and much cheaper than the alternator.

 

[808MP5]

It's your alternator. The tow truck guy is correct. After jumping the car and disconnecting the negative terminal the alternator should provide enough juice to keep
the car running.

An alternator is going to cost you about $120-$200 depending where you get it from. Iirc I got mine from napa for $118 after core return. As for labor charges expect to pay for a full hour. Hourly rates at garages vary between $60-$80.

If you are familiar with handling a ratchet youcan do it yourself. Remove the stock strut bar. Unbolt the cruise control and move it out the way. Unplug the alternator. There is a tensioner bracket on the alternator. Loosen it so you can get the belt off. Unbolt the alternator and put the new one in. Just do what you did in reverse.

There's pretty much only two ways to puzzle it out of the engine bay. Either the top or bottom. Trust me the top is easier.

Good luck and have fun.

 

[loco21]

Check the terminals same thing happen to me twice first time the battery light came on it was the terminals they came painted red and black from autozone I scracht them put it back problem solve. second time the car went off on the middle of the road on a red light it was the terminals loose. Looks like the alternator have some kind of braker to protect itself.

 

[808MP5]

it is not the terminals... must read the original post to see what was done... car runs on a jump start which means the battery has a little bit of juice but not enough to run the car... but when disconnecting the negative terminal the car dies... perfect example of a dead alternator...

regardless if it was the terminals or not... the car does not need a battery to run... just a properly functioning alternator... the battery is just there to start the car and keep accessories running if the car is not on

 

[justanothermp5]

yea def the alternator, my GF's mom had this problem, her car would start with the charger hooked up and stay on when i took it off but wouldnt start by itself
turns out after i took it to advanced auto that the battery was completely dead, so its not the terminals or the battery

alternator isnt hard at all to replace, its even easier once u take the intake mani off but that can be a lil hard to take off lol

 

[slavrenz]

If the battery is really really bad the alternator might not be enough to keep the car going, as the circuit is basically broken by the dead battery. Make sure that the tires are properly hooked up to the battery, and the terminals are clean. I've had similar problems from loose or dirty contacts on the battery.

Wtf?

 

[bucksatan]

^Hah, spelling fail. Wires, not tires.

Original post corrected.

 

[SocialStealth]

I have a used alt I can sell you. Works fine. I bought a h/o for my stereo system so I don't need the stock alt. pm me if interested.
Its from my 02 protege (not p5), but I dont think there will be any fitment issues.

And if the alt has gotten that bad, most likely it has been charging the battery incorrectly and destroyed the battery. So you might need another one of those as well.

 

[localkineguy]

It's your alternator. The tow truck guy is correct. After jumping the car and disconnecting the negative terminal the alternator should provide enough juice to keep
the car running.

+1, check a junkyard for a cheap one. Did this for my Accord a while back.

 

[YelPro03]

It was indeed the alternator. It was $275 for parts and labor.

 

[808MP5]

$275 is on the high end but atleast you got it fixed

 

[YelPro03]

The shop I bring all my cars to is great. They're not the cheapest but they're the best and my family have been going to them for well over 10 years. I'm pretty comfortable with the price because I know they did it right and didn't use any cheap parts.

BTW, the battery is fine.