since i fried my alternator and battery and its all fixed now and i still want a system. would buying a volt meter at autozone tell me if im frying it again or not?
No, you need to be more aware of your surroundings. Before your alternator/battery goes, it'll give off warnings. For example, when you blast your stereo, the lights on your car will dim with very bass note. That is a clear sign you should never ignore. You either turn down the volume or get HO alternator. If you ignore it, then your starter battery will get worn out. After that, your alternator dies. Having a voltmeter/DMM will help you monitor the voltage activity in your car. When your car is running, the voltage should be around 13.8v - 14.2v. When the stereo draws too much current, till force the voltage to drop all the way to 12.5v (your battery). If you keep that up, the battery will lose it's charge. When it falls below 10v, the battery will need to be replaced. No matter how much you recharge, it will not hold any power.
i was just wondering because i dont want to blow my alternator again but it was only 150 watt amp so it may have been an old alternator or faulty wiring. im wondering if i can buy anything that tells me if im going to blow it again
Listen to the warning signs. Lights will dim, RPM will be rough, and internal lights won't be as bright. All signs of alternator being pushed to the max.