car won't start

nutty1

my sons car had a new battery last week cos it kept not starting. but this morning it won't start again. we pushed it then it started and was ok to get him to uni. when he finished uni it won't start again without being pushed. once it starts it is ok. what could be wrong

anewman

Sounds like it could be the alternator, as the battery isn't getting charged. Could be as simple as needing the voltage regulator replaced or maybe the whole alternator needs replacing.

Either that or the starter motor.

nutty1

he had the alternator checked when he got the battery and they said it was ok

jarrod1

faulty/blown lights can put a permanent drain on the battery. Check all interior and exterior lights, dont forget the boot light and rear number plate lights.

anewman

A good auto electirician should be able to tell where any drain is if you can't find it. As jarrod1 says a common thing is the boot light, take off parcel shelves and observe when the boot is shut if the light goes out. A quick fix is to remove the bulb.

nutty1

he says hes not got a light in the boot

nutty1

its making a clicking noise instead of turning over. the last battery he got was only two months ago but when it won't start last week the garage said that one was a faulty battery and so he had this one fitted last week.

anewman

An easy test of the battery is to switch on the headlights, try to start the engine, if the headlights go very dim the battery is probably flat.

If the starter motor is working ok and turns when the battery is charged, it points to battery drain or a charging problem.

Also, if jump starting with jump leads doesn't help the starter motor turn, I would suspect the starter motor. I have read anecdotal accounts saying whacking the starter motor with a hammer can sometimes get them turning again, but I would obviously advise caution as there's the potential for damage to the car.

nutty1

we've just done that with the lights and they do go dim. but the battery is only a week old. what should we do. i don't know anything about cars, i don't even drive. and this is my sons first car and he is only 19

djheath

The best thing to do to diagnose the problem is to buy a multimeter. like this one:
http://www.amazon.co.uk/Draper-52320-Digital-Multimeter/dp/B0001K9UZA/ref=pd_bbs_sr_5?ie=UTF8&s=diytools&qid=1197397083&sr=8-5
They are inexpensive and very very useful.

Using the multimeter you can test to see if the battery currently has 12volts. If so and you cant start the car then it is likely to be a problem with the starter motor. If you hear a click but no "whrrrrrr" then the solenoid is probably stuck. Tapping the smaller cylinder on the starter motor with a Birmingham screwdriver "hammer" will most likely release the solenoid and the car can start. The problem is likely to happen again and you will need a new started at some point soon.

If you do get the car started, with the engine running, test the voltage of the batter. Its hould read a voltage of around 13 to 14volts maximum. If it does, it shows the alternator is doing its job properly. If the value is less that 12 volts or the voltage is way over 14 volts then the regulator or alternator are at fault.

djheath

kathrynt wrote: »

we've just done that with the lights and they do go dim. but the battery is only a week old. what should we do. i don't know anything about cars, i don't even drive. and this is my sons first car and he is only 19

Despite what has been said above, I would be more inclined to say that the starter motor is at fault then. If the lights are bright before he starts the car, then go dim, when he trys to start it, that shows, power is being sent to the starter motor. The starter motor is trying to draw the power away from the lights hence, why they go dim.

If the battery is dead, then it would mean the lights would be dim at the beginning.
But, I may be wrong on this!!! Its been a while since I was in this situation!

Also, if the alternator was at fault, the car would not keep running. If the alternator hadn't charged the battery enough to start the car, when you got it started after the jump start, the battery definitely wouldn't have enough charge to keep the car running and it would quickly die like a flan in a cupboard.
My money is definitely on the starter.

What car is it by the way?