Battery or Alterntor ?

[Supernova]

A problem has started with my clio 182 today.

The battery and stop lights come on when the car is at idle but when you rev it or driving the car the lights go out.

The voltage at the battery is 12.4 volts at idle and when you blip the revs the volts go up to 14.5 volts but then go back to 12.4 volts.

The car starts fine with no hesitation and drives fine.

Is it the alternator or battery thats at fault ? Am hoping its the later.

Thanks

 

[Owen92]

Sounds like the alternator. Should be putting out more than 12v at idle. Should be 14ish volts from what I remember of a 12v system.

 

[ady347]

+1 alternator

 

[Llewellyn]

When I test the alternators on these, I usually get in the high 14's (14.7), so 12v seems a little low.

 

[imprezaworks]

Alt

 

[Supernova]

Thanks for the replys !

Swapped the battery today with another clio 182 and its still got the same prob.Is intermittant though with sometimes going upto 14.4 volts and the dash lights are out but when you put the headlights on the voltage drops to 12.4 volts and the battery light comes on again.

Priced up a bosch alternator at euro car parts at £150 so looks like its away to get ordered.

 

[Dan]

Damn it, this has just happened to mine.

Light goes off at about 1500rpm does that mean it's charging ok at them revs?

 

[imprezaworks]

You will notice it more at idle. It will get worse, caught me out on the motorway, raining and four up (passengers). Worth checking the alternator strap first though

 

[Supernova]

I got a new alternator from renault and a battery aswell from euro car parts for good measure.Changed them over and cars been fine since.

 

[Dan]

I think the bearings have gone in mine, it's making a low tone whine on idle and the my AC delete belt slipped a bit on startup so it's a bit less free moving than before. I'm just gonna put it back in the garage for a bit and collect up the parts needed over the next week or so as mines a 2nd vehicle.