Chrysler Repair: Chrysler Aries 1987 - alternator or battery?, metal surfaces, dash lights

Question
i am trying to figure out if the problem with my car is the battery or alternator.  keep in mind that right now it is -30 and i don't have a block heater.  the car will start when boosted and will start usually during the day after it has been boosted in the morning.   but will not start when it has sat over night.  at these times, it is completely dead (by this i mean no interior lights or chimes or dash lights etc.), but starts fine when boosted.  

i just replaced the battery yesterday but the same thing happened this morning. if it was the alternator, wouldn't there still power (lights, chimes etc.)?

thanks,
Meghan

Answer
Hi Meghan,
I would suspect that the battery post/clamp interfaces or that the ground wire from the battery (-) post to the nearby metal frame are either loose or corroded such that when it really gets cold the battery is not really connected to the circuits of the car, otherwise there would be some signs of life, even at -30. So I suggest that you get a simple tool called a battery post brush which has two different wire brush types, one for the posts and one for the clamps, and that you shine up those interfaces. Also buy and apply some battery post anti-corrosion compound to the interfaces of the clamps/posts and then reconnect and tighten the clamps. Then notice a couple of wires from the (-) post clamp:one goes to the engine/transmission the other goes to a grounding bolt attachment nearby on the body. Make sure those wire eyelets on the ends of the wires are shiny as well as are the metal surfaces to which they are bolted. You might well put some battery compound on those interfaces as well, then reattach and tighten.
I don't think it is the alternator, otherwise the red warning charging malfunction light on the instrument cluster would be "on" while you are running the engine.
Without such a warning light the alternator is doing its job. If the alternator is bad that warning light is what would be the tell-tale.
I believe that your battery is not well connected at all the points I described above. Also look at the attachments of the battery cable clamps to the ends if the wires themselves as you could have corroded battery cable wires at this point in time, 20 years of age.
Roland