Alternator Problems on my Fiat Marea 1.8 16v 115 ELX

[montrose]

Can anyone help me? i recently (3 weeks ago) had to change my car battery as the one that was in the car was completely discharged and wouldn't charge even after a long run. I bought another battery which seemed to do the trick but 3 weeks later that battery is also dead and starts only with a jump start. The car will not even turn over as there is no power to do it. I was thinking that it might be the alternator !!! but before i go and buy one can anyone help me check how to tell if it really is the Alternator that is the problem!!!!!.

[dans1977uk]

If the red battery light is not coming on when you're driving it's unlikely to be the alternator, though to check start the engine and with the engine idling turn on everything electrical (lights, heated screen, aircon, fans, radio etc..) and see if the light comes on then. If it does take it to a local garage with a good reputation and ask them to check it for you.

It's more likely that you've got a bad earth somewhere in the car and that's slowly draining the battery. Ensure that the terminals are greased and that the earth lead (thick black cable from battery to the car bodywork, chassis or engine block) is not corroded.

That's about all I can think to suggest! There is always a chance that your new battery was faulty too!

[qapmoc]

Sounds like you have two choices about now, you can either take the vehicle to someone to have it checked out or buy a cheap multimeter to allow you to check it out yourself.

If you buy the multimeter set it to dc volts and connect it to the battery, with nothing switched on with a good battery it should show at least 12 volts dc, probably more . Now switch on the headlights and the voltage should drop, switch off the headlights. Now start the engine (fast idle speed) and the voltage should go up to about 13.75volts dc and if you switch on the headlights it should not drop enough to notice. If the voltage does not rise when the engine is running you can be pretty sure the alternator is dead.
But I suppose you did check that there are no loose wires which have come off the alternator etc... or that the alternator drive belt is not loose and slipping.