182 Battery Not Charging

[Martyn2306]

Hi Everyone,

I'm not sure if this has been covered before but need a bit of help.

Last night on my way home from work the STOP, SERV, ABS, AIRBAG & Battery Charge Light all illuminated on the dashboard followed by the electrics going haywire.

I managed to limp home and discovered the battery was flat, gave it a quick charge and it started fine but still with the same lights on and no headlights heater etc.

I'm assuming the battery is not charging but the cause of this is really what's worrying me. I had a quick look at the alternator and the belt appears to be driving it and not slipping but I just wondered if there were any other known electrical gremlins with these cars?

I know its a bit vague but hoping its something easier and cheaper than a new alternator!

Cheers,

Martyn

 

[deaddog]

I had similar symptoms a couple of years ago. When I checked with a meter, the alternator was putting out 14V at tick-over but 18V when revved, i.e. the regulator on the alternator had failed. I was lucky as once I replaced the alternator everything was fine, the excess voltage could easily have caused a lot more damage.

BTW the alternator seems to be a weak point on these cars I've replaced mine 5 times in the 11 years I've owned my 172.

 

[Don]

The alternator...almost certainly. Just because the belt is on there and it moves freely, doesn't mean that the alternator is working properly. Its about £50 for a second hand one from Renparts, its better than Renault's brand new one (which will be well over £200 and still might have issues...)

 

[Martyn2306]

Thanks for the swift response!

I'm just off home to test the voltage output so will let you know the results. Tbh I expect it to be the alternator but we shall see. Could a loose earth or something along those lines cause this?

 

[Martyn2306]

Well an update. Reading on the battery was just over 12v, reading on the alternator was just over 11v. So definitely the alternator!