Electrical Issues - '90 535

[hdaemon]

My '90 535 (210k mi) won't start on its own, and I"m not quite sure what I should be looking at. The problems started yesterday.

The car started fine in the morning, but when I came out after work, it refused to start. No response at all when turning the ignition. The starter motor wouldn't crank, nothing. Just a dimming of the console lights. When AAA got there, we were easily able to get the car started from a jump pack.

Presuming the battery was drained, I drove the car for about an hour to charge it. However, when trying to restart it after it has been stopped for 20 minutes or so, I had exactly the same symptoms. No starter motor, just dimming lights. Again, with the help of a friendly individual in the parking lot, I was able to easily start the car with a jump.

Got home, parked the car, and realized that something was making the door lock solenoid go nuts (the lock was literally vibrating), so I disconnected the negative terminal of the battery and left it for the night.

When I came out this morning and reconnected the battery, the car started up. Once. Then it went back to exactly the same symptoms.

I pulled the battery and took it over to Autozone to have a load test done. At least according to their test, the battery is fine.

So the question now is: Where to from here?

What would possibly be wrong that would cause the car to start easily every time I was jumped, but would refuse to allow it to start from the battery? With the battery connected, I get voltage at the terminal in the engine bay (Not sure how much as my only voltage meter is an exceedingly cheap analog one).

Suggestions?

[Jr ///M5]

Reguardless of what Autozone says.....REPLACE THE BATTERY. Use the Autozone replacement ..group number 46???? I can't remember for sure. Just give them the year and make of your BMW and make sure it's the vented model. Take care to install the vent for the battery properly.

If that doesn't work, call me on my cell and I'll refund your money.

Jr

[guinness]

I had the same thing happen to me a few months ago, you need a new battery.

[Flamin'Cow]

I have had a similar problem - I replaced the Solenoid on the starter motor and now it starts fine....

[winfred]

could be a dieing battery (4 years old or so id replace it) or a power drain from the car drawing it down, a crapping out battery can be tricky to diagnose and i have seen it too many time where the battery will pass all kinds of tests and still be bad (had a customer with a e39 that was a tech at a dodge dealer run the battery several times on the dealers multi thousand dollar battery tester and it passed every time, but it was still wound up being bad after wasting way too much time screwing with it)

[hdaemon]

could be a dieing battery (4 years old or so id replace it) or a ...

The battery is 3 years old. It's a replacement one from the dealer, and I've seen it mentioned elsewhere in the forum that these batteries have a tendency to die after only a few years. I think tomorrow I'll likely go over and pick up a new battery. Hopefully that's the only problem.