What would make a alternator go bad??
11-25-2011, 12:57 PM
#1
What would make a alternator go bad?? Hey guys I was wondering what can cause a alt to go bad? My car has 41k miles , basic bolt Ons, and is a 02 . Ever sense it got cold out here in Germany (28*) my alt has been charging at around 16, but once the car gets a little warm it doesn't charge too high .. But the batterie needle moves with the rpms and the dash board lights dim and flicker(idk if that's common?) and the car shake a tid bit..and this All started when it got really cold . I even went got a new batterie and it did the same thing :/ So what makes alternators go bad?
11-25-2011, 05:46 PM
#4
Your problem is most likely old age. Even though you have low miles, the components of the car still age, rubber hardens, metal corrodes, etc. (If your car is stored outside and exposed to temperature extremes, this can cause parts to be weakened.)
If you watch the videos on Alternatorman's youtube channel, you'll learn more about these things than you ever wanted to know. http://www.youtube.com/user/alternatorman?blend=1&ob=5
Alternators have three key parts - the generator (makes AC electricity as the rotor turns inside), the rectifier (converts the AC electricity to DC), and the voltage regulator (keeps the voltage at a constant level).
Since your voltage is high to start and settles down, it sounds like the voltage regulator in the alternator is going bad. (If it changes when it heats up, some part of the circuitry is probably cracked/cut and gets in order when things heat and expand.) Since the mechanical parts of the alternator are low miles, you might simply replace the voltage regulator if you have problems getting parts where you are. (There are videos on Alternatorman's site on how to do this and his company will ship the parts overseas. He also has videos that show how to test and confirm its the regulator - but that gets a bit technical.)
The stock alternators are "small" but perfectly adequate for the job on a car with normal electrical demands. If you don't have mods that require more power, than putting a "big" alternator on the car will just waste gas. (Having more power gives you nothing if the car never makes a demand for it.) If you are after improved durability, you can get top grade voltage regulators: http://store.alternatorparts.com/regulator-17.aspx and/or heavy duty rectifiers: http://store.alternatorparts.com/rectifier-19.aspx
If you watch the videos on Alternatorman's youtube channel, you'll learn more about these things than you ever wanted to know. http://www.youtube.com/user/alternatorman?blend=1&ob=5
Alternators have three key parts - the generator (makes AC electricity as the rotor turns inside), the rectifier (converts the AC electricity to DC), and the voltage regulator (keeps the voltage at a constant level).
Since your voltage is high to start and settles down, it sounds like the voltage regulator in the alternator is going bad. (If it changes when it heats up, some part of the circuitry is probably cracked/cut and gets in order when things heat and expand.) Since the mechanical parts of the alternator are low miles, you might simply replace the voltage regulator if you have problems getting parts where you are. (There are videos on Alternatorman's site on how to do this and his company will ship the parts overseas. He also has videos that show how to test and confirm its the regulator - but that gets a bit technical.)
The stock alternators are "small" but perfectly adequate for the job on a car with normal electrical demands. If you don't have mods that require more power, than putting a "big" alternator on the car will just waste gas. (Having more power gives you nothing if the car never makes a demand for it.) If you are after improved durability, you can get top grade voltage regulators: http://store.alternatorparts.com/regulator-17.aspx and/or heavy duty rectifiers: http://store.alternatorparts.com/rectifier-19.aspx
I will look it over!!
11-25-2011, 10:13 PM
#7
Yea, I just recently changed my alt and kept the core so I can rebuild the stocker (at the stock output) as a HD model when I get my garage. (Hopefully soon.) I'm sure diodes in the stock rectifier is bare-minimum. Lots of people have posted here with regulator problems, as well - but I can't imagine there being any chronic issues with the generator section. (It looks pretty stout.)
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11-26-2011, 10:59 AM
#8
i had the same problem with my 02 TA with 25k on the clock. after i pulled the car out for spring the volt guage was reading high and bouncing around after it got warm dimming lights ect. the only thing i could think of that could have caused this was that i put a battery charger on it set it on engine start and cranked the car until it started. once it started i removed the charger and let the car run for a few minutes. i'm pretty sure in that short period of time that the car was running with the charger still hooked up i overloaded the voltage regulator and fried it . long story short, i replaced the battery and the regulator in the alt and everything has been back to normal all season. hope this helps.
