The car: '98 Ford Mustang 6 cyl with 145,000 miles. When cold, it does take quite a bit of cranking before it finally turns over.
The short version: The battery is not charging. Replaced alternator. Battery and new alternator both test good.
And the Long Version of the problem I’m having:
6 months ago, on the way home from work, I ran out of gas. While I walked to get a gas can, I left the lights on. The battery was too dead to start the car by the time I returned, so I got a jump. A few days later, the power was dead and I realized that the negative battery cable connector was loose. So I tightened it and everything was good.
6 weeks or so ago, my daughter took the car out, and it wouldn’t start for her on her return trip. So I went out thinking that the cable had come loose. That terminal (the negative) was badly corroded. I jumped it, got her home, and the next day I cleaned the terminal with baking soda and water and reconnected the cable. The connector was pretty loose, so I tried to tighten it and only wound up crimping it to an oval shape. But it went on tightly and I thought I was good.
A few days later, the battery was low again, so now I thought that the connector was not making a good enough connection. So I went out and bought a new connector. I had a hard time getting the old one off, and finally had to take a hacksaw to it. I got the new connector on and it ran fine.
A few weeks later, it wouldn’t start again. We jumped it and got it home. Everything looked good and well-connected. I jumped it again and took it to Les Schwab to have the battery tested, thinking that it was old and not doing well. They said battery tested fine but that the alternator failed. The guy there convinced me that I could replace the alternator myself.
So the next week I bought a new alternator from AutoZone and installed it. I’m pretty sure I did it right. The belt is tight and the alternator spins at high speed. It doesn’t wobble or seem to vibrate.
I took the old alternator back to AutoZone and had them test it on their machine. It failed. So I thought I was good. I jumped it and went on a nice highway-speed drive for an hour. I drove it for a week before I had any further problems.
But then it started turning over weakly. Sometimes it would start before running out of juice, sometimes not. I jumped it four or five times that week.
Last week, I unplugged all of the wires out of the alternator and replugged them. I pulled out all of the fuses and checked them. Then I took it back to Les Schwab for another test (after jumping it). They said it tested fine, though a little low. He offered to put it on the charger for a few hours and test it again. And it tested fine again.
So, I hoped that the unplug-replug had worked and drove it this week. But it didn’t. It started weakly on Wednesday morning, and wouldn’t start Wednesday night.
The battery doesn’t seem to get worse if I leave it overnight, or even for a few days. If I jump it, drive it for 30 minutes it has enough juice to immediately restart the car (it catches and starts running right away though), but it won’t have enough electricity to run the starter long enough in the morning. This wasn’t a problem before.
So after that long description, do you have any ideas? Did I get a bad alternator? Need a new battery? Do I need to trace down a broken wire?
Any help you could offer would be of great help!