It just won't start

I am again having trouble with my 1999 Mazda Millenia. I thought that it was the battery and tried to jump it, but it just wouldn’t start. Now what the car is doing is when I turn the key to the “ACC” part of the ignition the radio works and so does the clock. When I turn it to “Start” everything seems fine until I try to crank it and it won’t start. It sounds like it’s trying to start, but it just won’t. Also, the head lights won’t turn on either and when I try to turn them on all power to everything else i.e. the radio or lights on the dashboard will die. And when I try to roll up the windows(I have to do this in the “Start” key position on the ignition) they roll up very slowly and everything else again will loose power. What’s wrong?

It still may be your battery. Unless you jump your battery with a car that has a fully charged, high ampacity battery and ‘superior’ (think thick, heavy, & expensive) jumper cables, you need a capable battery in the nonstarting car to provide the provide most of the starting amps. In fact most jumper cables should be labeled ‘charging cables’ because they can only be relied on to charge the nonstarting car’s battery. One way to verify the condition of the battery is to monitor the battery voltage while the key is turned to the crank position or the head lights ‘on’. If the voltage is significantly below 9 volts DC, recharge the battery and check again. From your description of the symptoms, the battery cannot even supply enough ampacity to run the head lights. The battery probably has a bad cell and will only read 10 to 11 volts DC unloaded after a lengthy charge.

Another possiblity to consider is that the battery clamp(s) and cable(s) cannot carry the current. Clean the positive and negative battery clamps and battery posts. If this does not solve the problem have someone do a voltage drop check with a load on the system to see if there is a voltage drop between the battery and starter.

Good answer. I agree, either the battery is toast, or you have a bad connection.

I am having a corrosion problem so I’m going to clean the clamps to the battery, but what are the battery posts?

The battery posts are the metal posts you connect the battery cables to. Your battery may have side mount connections so in that case the connection is slightly different. Be sure the cable and the battery connection surfaces are clean. I recommend you use a battery cleaning brush which you can get at a auto parts store.

If the battery is more than 4 years old you may want to consider replacing it. It sounds like it is low on charge at least and you should charge it up using a battery charger. If you still have cranking problems after doing those things then you need to check for a problem in the accessories power system.