Car won't start with new battery. Only jumping starts it

Question

Over the past little while my car was taking more and more attemptes to start until it finally would not start. Replaced the battery and cleaned the connections but it still won't start. The only way i can get it to start is if i jump it then it starts right away. what could it be?

Answer 1

I'd suspect that your battery earth/negative lead has a poor connection to the car bodywork. By correctly connecting a set of jump leads to a working car, your car gains a good attachment to the working car's battery positive, and also its battery negative because (observing correct jump starting procedure) the negative lead on the "dead" car is secured to somewhere other than the battery negative post.

     .--------------------------------<[DEAD CAR ENGINE BRACKET]----.
    (-)                        .------------^                       |
[WORKING CAR BATTERY]     [dead body]###--------(-)                 |
    (+)                   (poor conn)    [DEAD CAR BATTERY]     [DEAD STARTER]
     '-----------------------------------------<(+)-----------------^ 

The "dead" starter gets good assist from the working battery via a good connection through the engine mount, to which the jump lead is connected. It supplements the poor connection it has to the "dead" battery via the bad connection

If you assert that you just connected the jump leads between the batteries, I'd say that there's a poor connection between the "dead" car battery connector and the "dead" car battery. Clean the "dead" battery terminals and also clean the inner face of the battery connector that grips the battery terminal. Ensure that the connector hasn't been overtightened in the past and is now ruined, giving a loose grip even though the securing nut is tight

ps; I appreciate that your new battery on the broken car, isn't a discharged battery (hence why I keep putting "dead" in quotes) - it's just an easy way to refer to it, in light of a typical jump leads scenario

Answer 2

This has happened in my neck of the woods a few times .University 1980s .OK the easy DIY new battery does not nail the starting problem .What the issue was that the starter motor was consuming much more amps than normal .When being jump started the car had 2 batteries helping so the battery volts during cranking was enough to fire the plugs .In one case the Joseph Lucas Starter motor was faulty .In another case a Delco Starter was at fault .In the third case I noted that the freshly recond tight motor was hard to turn by hand .A nigh quality battery and time fixed this .

Answer 3

Agree with both previous answers-it could be either-remove drive belt and. See if it starts-may have a siezed alternator-ideally, check voltage drop between battery + and starter + when cranking-this will let you know if the starter is pulling too many amps