alternator replacement

[wetamup2k3g]

u could always check it the old fashion way and crank the car remove the positve battery cable and if the car cuts off the alt is bad. just saying. but a bad ground a bad starter a negative dead cell in ur battery any thing my battery had a dead cell in it and it was tested fine but it wouldnt charge

I would NEVER check an alternator by disconnecting the battery, you could fry your entire electrical system (rare, but possible). The battery absorbs any AC current the alternator may be putting out due to fried diodes on the rectifier bridge, so if the battery is removed, the entire car may be subject to AC current, and electronics don't like AC current. You could fry the radio, the ETACS, the PCM, all that. Furthermore, removing the battery may even fry those diodes, making an otherwise serviceable alternator bad. Yes if the car cuts off the alternator is bad, but you won't know if it was good before you disconnected the battery. Just because it hasn't happened before doesn't mean it won't happen this time. It's not a good thing to do with today's computerized cars, which is why it's an old method.

Read these links for how the charging system works, how to check an alternator and each one has a warning about disconnecting the battery to test an alternator.

http://www.troubleshooters.com/dont_...ct_battery.htm
http://www.wikihow.com/Check-an-Alternator
http://www.bcae1.com/charging.htm

Hope this helps.

[Bobby~d]

Great info there^^^^

[BLOCK8732]

Could the PCM be the reason why my car won't charge

[spdracr]

I don't see how the PCM would effect the charging system.

[twisted_galant]

u could always check it the old fashion way and crank the car remove the positve battery cable and if the car cuts off the alt is bad. just saying. but a bad ground a bad starter a negative dead cell in ur battery any thing my battery had a dead cell in it and it was tested fine but it wouldnt charge

DO NOT do this. Disconnecting the negative cable on a running car generates an electrical spike. This spike has to go somewhere, could be one of your computers. Hell of an expensive risk to find if you got a bad alt.

[BLOCK8732]

Been googling this problem and some mitsubishi techs have been saying that the pcm could cause a problem with the charging system. Just wondering if anyone had this happen before. These pcm's are crazy for these cars. I've read that it would be a good idea to keep an extra one in your car because they go out sometimes

[dknight3]

nvm