Foreword: I have very little knowledge about cars and how they work. Also sorry if this is long, I want to include every detail I can because this isn't making sense to me.

So a few months ago I'm driving along in my Cougar when I notice my stereo is starting to get quieter. A few seconds later my windshield wipers start slowing down and my window is fogging up (the defroster stopped working). I try rolling the side window down and up and find that is also very slow and now they almost stop working all together. I turn around immediately and start heading home. Halfway back, the car starts shaking a little bit, and is having trouble when I try to give it gas. It gets so bad I have to pull into the nearest parking lot where it promptly dies on me. I am then unable to restart it, so leave it there while I get a ride back home.

6 hours later I go back with my dad to get it towed somewhere, and I try to start it again. This time it starts and I am able to drive it home where it dies one last time. All the while it was shaking and stuttering for whatever reason (I actually thought it wasn't going to make it).

Basically it's been sitting in the driveway until last week when I finally got a multimeter and tried to figure out what was wrong on my own. At this point the battery was completely drained, even though it was very recently bought. I hooked it up to a portable battery charger and waited until the meter read 11.90V and put it back in the car. When the key was in, the dash lights did come on, though dim, although it wouldn't start. It wouldn't even turn over. I tested the battery again and this time it read 9.80V. I started to think it might be an alternator problem. So my dad and I tried to jump it with his car. The lights came on again this time they were the proper brightness but still no turning over. Then my dad took the negative clamp that was on my car's chassis and clamped it to the negative terminal of my battery. I always thought that was something you weren't supposed to do, but my dad said it was fine and I trusted him (note: He doesn't know much about cars either but more than me). Lo and behold, my car started. It was shaking a little bit, and as soon as I gave it gas it died, but it was something. I checked the battery again and it was still 9.80V or something close enough to that.

Now I don't really know what the problem could be coming from. If I try to logic it out, I think it could still be a problem with my alternator, and his car was just able to keep my battery charged until I tried to give it gas. Am I close? Or could it be a problem with the starter? Or even just the battery cables being lose or frayed? It's a pretty old car with a lot of miles but it's been very well taken care of, both my myself and the previous owner, and it's a 2.5L Manual if that matters any.

  • From the first part of the story I suspect you have a bad alternator, which in turn killed the battery. Also the fact that moving the jumper cable to the battery may indicate that you have a poor connection someplace. When you say chasis do you mean the metal of the car? (the best place for the jumper ground is right to the engine eg the alternator bracket). In any case I've never seen a car batter as low as 9.8 be successfully returned to normal life. Assume it is toast, hopefully you get something for it under warranty.
    – agentp
    Sep 25, 2017 at 20:04

2 Answers 2


Put the battery charger back on the battery and leave it there until it gets above 12.5vdc. You can leave it in the vehicle to do this if it's easier for you. Once it gets charged all the way, attempt to start the car. If it starts, check the voltage at the battery with it running. Keep the multimeter in place and watch what it does. If the voltage stays above 13.1vdc, your alternator is most likely in good shape. If the voltage is down in the 12.5vdc area and is slowly dropping, the problem is your alternator.

If the battery does not get above 12.5vdc after charging for several hours, take it back to the place where you bought it and have it replaced under warranty because it is most likely bad.

If after the battery has reached 12.5vdc charge and it won't start the car, check all of your battery cable connections. More than likely one or more of them need to be cleaned and or tightened in order for them to have a good connection to the battery and have the ability to use the power stored there.

One other caveat, there may be more than one thing going on here, so don't just rule something out. You could have two problems ... or three. Great fun.


It's your fuse behind the engine, between the alternator and battery on the positive wire. It's a 175amp fuse.

It can be tricky to change if you aren't mechanically inclined .

  • I said a bitch to cange it didn't say it right Jan 21, 2019 at 4:32
  • I have edited your post just to clarify, and to make it easy for new visitors to read. Some may not know what alt is short for, etc.
    – Rory Alsop
    Jan 21, 2019 at 13:18

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