Hello folks!

My wife's '01 Elantra engine will only start with jumper cables connected from my other car. if the jumper cables are removed after starting, the engine stops.

My wife says she's 'always had trouble with the battery' in the car, and that it's been replaced a number of times. What simple diagnostics can I perform with my basic testing gear (multimeter etc) to see what the root cause is here?

Could it simply be another replacement battery is required? How can I test for this?

Could it be the alternator? How can I test for this?

Could it be something else? Cables, fuses, solenoid, etc? How can I tell?

What other clues should I be looking for to narrow down the root cause?

 

Update: Some more Googling so I tried this:

Measure the voltage across the battery after jumpstarting the dead car.

I did this, the voltage reads as 13.8V.

 

I just had something like this on my 2007 Elantra. Battery charged but wont start. Will start when jumped from another car. After turning the Elantra off and attempting to start on its own it displays the original symptoms (dash lights all started flashing randomly and weird buzzing noises, engine not turning over).

My solution was to replace the connector from the ground terminal of the battery to the chassis. In my model the ground on the battery only has one thick braided wire running from the ground terminal to the chassis. This cable was badly corroded on close inspection. I suspect the corrosion only left JUST enough material to carry enough current to start the car until the other day when it finally failed.

Other options could be that the clamps aren't tightened enough onto the battery terminals and when you boost the car the clamps are providing an additional pressure. Battery terminal shims are an option here if tightening doesn't work.

Hope that helps you!