I've seen rebuilt alternators that have a bad diode which can drain a battery over night. Make sure the battery charge warning light is not glowing a little by observing it in the dark with the motor running. The voltage reading at the battery posts must be higher than 13 volts at 1,500 rpm or you have a bad diode and the battery isn't being charged enough and is draining back down through the alternator with the motor off.
If we need jump start every time even with known decent battery and alternator! Then odds are we have some sort of parasitic power drain. Get circuit checked by auto electrician. They can test for milliamps flowing with engine off. Then locate circuit using power. Likely hood is we are losing battery charge overnight thus jump from another gives us the voltage increase needed and amps to crank starter. They can check out battery at same time and alternator function.
check your main power cable ( pos. ) going from the battery to the starter. the cable ends could be loose, or the cable may have melted against something hot like the exhaust manifold. if this is the problem? it will usually start when cold, but fail to start after being driven or intermittently.
Could be a bad solenoid. If you can pop start it then its probably the starter. If it can be jumped then its not likely the plugs,wires or injectors.
You may want to consider using a good vehicle software product to keep you up to date on your car maintenance. I use Automotive Wolf Car Maintenance software.
http://www.automotivewolf.com
My car (a 1996 Chrysler Cirrus) has a brand new battery, a brand new alternator, and a properly functioning starter yet it never seems to start anymore without first being jumped. Any ideas as to why this might be happening?
