How much would it cost to replace alternator in Toyota 4Runner?

i recently changed my car battery and it was drained overnight. i have already checked the fuses and they were all okay, and was wondering if the alternator is the one that is causing the problem. how much does it cost to replace the alternator in my Toyota 4Runner?

i would appriciate any help.How much would it cost to replace alternator in Toyota 4Runner?a bad alternator will not cause your battery to drained overnight. if your battery is new and dead the very next morning, could be that you have a parasitic draw. meaning there is something that is staying on, like a bulb, that should not be. a charging test will tell you if your alternator is bad.

to do either of these tests you will need a DMM (digital multimeter).

to test for parasitic draw: disconnect the negative battery cable. set your DMM to amps. place one lead to the negative cable end, and the other to the negative battery terminal. if you get more than about 37 mili amps, you have a parasitic draw somewhere. start disconnecting stuff to see if it goes away. when it does, that is the system with your draw.

to test your alternator: preferably a hand held starting/charging tester is the way to test your alternator. but if you don't have one, you can try with the DMM. with the engine running, turn all accessories on (radio, A/C, lights), place your red lead of the DMM to the positive battery terminal and the negative lead to the negative battery terminal. you should get around 13-14volts. if it's around 11 or 12 or under, your alternator is probably bad.

good luck!