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If both the alternator and the battery are good, either the alternator isn't turning fast enough (slipping belt or engine idle speed too slow), or you have a wiring problem.
To check your wiring, look for the "1" terminal on the back of the alternator (left side of spade terminal connector). When you turn the ignition key to the run position without starting the engine, the alternator warning light should be at full brightness. If the bulb is burned out, the alternator will not get the excitation current it needs to start up (it goes through the bulb). With the engine running, you should measure 12 Volts at the 1 terminal (this is the excitation terminal).
Another thing to check is whether the battery charge wire is good. If it is corroded inside at the battery clamp end or burned out, you won't get charging even though the alternator appears to be working. If you don't have an ohmmeter, you can make a quick test by adding a new 8 AWG wire between the output terminal and the battery clamp. If the battery now charges, the original wire is bad. If this works, I recommend installing an inline fuse at the alternator end no larger than the largest size used in your electrical system, just in case something happens to the jumper wire. That way you won't burn out your alternator.
The heater/AC issue could very likely be a separate problem, but inadequate power may keep that system from running properly. (Note: low idle speed or belt problems will also be detrimental to AC performance.)
It sounds like what you fried is the diodes on the alternator. You are probably due for a new alternator. On the bright side, it's much cheaper than the computer.
You didn't mention how far if any you drove since installing battery. First jump start, put voltmeter in battery while idling - should read 13.1v-15.8v. Anything less, replace alternator. If good, load test new battery.
This means that your alternator is not charging anymore and likely needs to be replaced. You may want to have the battery charged then checked as well. Sometimes a failing battery can cause the alternator to fail because they require a higher charging cycle that can prematurely burn out the alternator.
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