2000 Maxima Battery refuses to stay charged

My dad bought this car 2 years ago and had to put an alternator on it the day we got it. He has since changed the battery twice and another alternator. The alternators were bad because they were checked. Now the car if it sits will not start. When we jump it off the car alarm will be on. When driving down the road the radio will also change stations without warning. We can’t get anyone to find the problem. We are thinking about pulling the power to the alarm system however we have been told that if we disable it the memory will be lost to the ignition and we will have to reprogram the key thus meaning no way to start it.

It sounds like the electrical system has an excessive current drain on the battery while the car is parked. I suggest you take it to a shop that specializes in electrical problems. They will be able to track down the trouble. It should be a pretty easy problem to find. I don’t see why there has been this much difficulty in finding the real trouble.

I agree - something is putting excessive load on your electrical system. I’m very curious about your comment about the radio changing stations without warning. Is it a factory installed radio? can you provide more details about that? Do you keep the radio on all the time?

Can you or your father work on the car? If so you can track down whatever it is draining the battery. On easy way to at least narrow down the problem is to get a wiring diagram, then buy, or make, a 12 test light with 2 leads, each lead needs to have an aligator clip on it. Remove all the fuses in the circuit, then disconnect the positive battery cable and connect the light between the positive post on the battery and the battery cable. Then carefully plug in the fuses one at a time. If the light starts burning very brightly you have found the circuit with the drain on it. Then all you have to do is to find out what in the circuit is causing it. And do all work with the ignition switch off.

Clever trick that will work - but before you pull out all the fuses - connect the test light and verify that it goes on (indicating a current draw somewhere). It would suck to go through all the effort of pulling and replacing fuses just to find out the light doesn’t come on at all!

And here is a tip - draw a picture of the fuse box and mark the size of the fuses and where they go so you get the correct ones back in the correct location. That is important.