Geo metro alternator

[R7000]

So far all of the advice I have recieved on this forum has been great. I have a 97 metro 4 cyl automatic. I think the alternator may be bad. I have read a couple of threads saying to check the belts first since if they are loose the alternator will not charge the battery and to remove the positive battery terminal to see if the alternator is bad. I have had the battery checked so I know it is ok. If it is necessary to replace the alternator how is it done?

[vgames33]

Don't unhook the positive terminal to check the alternator! This used to work on older, non-computerized cars, but not anymore. Unhooking the battery (while the engine is running) can cause voltage spikes which may harm your vehicle's solid-state electronics.

Take the car to a parts store and ask for an in-car charging system check. They should have a VAT40 (or equivalent) that can be used to check voltage and amperage output from the alternator.

[bigsmellyman]

Check the alternator using a voltmeter. Before you start the car, check the battery voltage it should be 12 volts. Start the car, check the voltage, it should be 13.8 volts. If the voltage doesn't go up when the alternator is turning the alternator is no good. Old batteries sometimes tesk ok when they are on their last legs.