Technical Fiat Punto 1.2L 2000 petrol Trip counter and clock resetting on startH

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Technical Fiat Punto 1.2L 2000 petrol Trip counter and clock resetting on startH

You may have a parasitic drain. Something is drawing current when the car is shut down and slowly running the battery flat. It's normal to have a small draw but things like incorrectly wired aftermarket radios or lights in the boot than do not switch off will draw too much.
Here is a procedure from the Guides section for chasing parasitic drains. https://www.fiatforum.com/punto-mk2...alternator-parasitic-drain-testing-guide.html
To check your alternator. At idle with no extra loads on you should have approximately 13 Volts at the battery. This should increase to about 14.4 at 2000 rpm and level off.

Thanks for response Brendan,

I don't believe it is parasitic as I did a test with multimeter (disconnected negative cable and connected from there to negative terminal, looking at the guide I'm supposed to do this with actually the positive terminal though ?). I'm pretty sure the drain was less than 50mA.

I did do a test guessing 2000 rpm (my cheap punto doesn't even have a rev counter). And I'm pretty sure the test was sort of inconclusive, if you read further back I mentioned that when I did the test the voltage did not get to anywhere near 14.4, and with electrics on (which I definitely need this time of year here in Finland) the voltage was only about 12.5V. Some people said this is normal but looking at the guide you linked me to, it said the voltage should only drop slightly. It dropped loads.

Summary,

- I don't believe anymore that it's parasitic drain but maybe I need to test between the +ve cable and terminal instead of -ve.

- Voltage at battery last time I tested properly with rpm was only about 12.v with necessary electrics on. When I tested this morning I was getting about 13.8v idle with no electics.

I have a suspicion that the alternator can't keep up under electrical load but this seems to be a point that not everyone agrees on (answers on this forum claiming 12.5 was okay under load but the linked guide for example and also haynes manual saying that voltage should drop only slightly.

Cheers,

Paul
 
Alternator brushes wear out eventually. If you are still on the original unit it owes you nothing.

No way to know as I only bought the car a handful of weeks ago :)

I think I'll be searching for an alternator.

Paul
 
Thanks for response Brendan,

I don't believe it is parasitic as I did a test with multimeter (disconnected negative cable and connected from there to negative terminal, looking at the guide I'm supposed to do this with actually the positive terminal though ?). I'm pretty sure the drain was less than 50mA.

I did do a test guessing 2000 rpm (my cheap punto doesn't even have a rev counter). And I'm pretty sure the test was sort of inconclusive, if you read further back I mentioned that when I did the test the voltage did not get to anywhere near 14.4, and with electrics on (which I definitely need this time of year here in Finland) the voltage was only about 12.5V. Some people said this is normal but looking at the guide you linked me to, it said the voltage should only drop slightly. It dropped loads.

Summary,

- I don't believe anymore that it's parasitic drain but maybe I need to test between the +ve cable and terminal instead of -ve.

- Voltage at battery last time I tested properly with rpm was only about 12.v with necessary electrics on. When I tested this morning I was getting about 13.8v idle with no electics.

I have a suspicion that the alternator can't keep up under electrical load but this seems to be a point that not everyone agrees on (answers on this forum claiming 12.5 was okay under load but the linked guide for example and also haynes manual saying that voltage should drop only slightly.

Cheers,

Paul

i remember a while back when i was measuing voltage with mes and it went as low as 12.3V with everything on so i think your alternator is fine, i had lower voltages on every punto like those in that guide and everything worked normal

alternator in that guide must have been high amp or something

reading your previous posts you wrote that voltage drops to only 12V with lights on, thats to low
 
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i remember a while back when i was measuing voltage with mes and it went as low as 12.3V with everything on so i think your alternator is fine, i had lower voltages on every punto like those in that guide and everything worked normal

alternator in that guide must have been high amp or something

reading your previous posts you wrote that voltage drops to only 12V with lights on, thats to low

It's hard to remember now, but I'm pretty sure that with only the lights on the voltage was okay, maybe around 12.5 or more, but not with the other electrics where it dropped too low. The problem is I need those electrics at the moment, front windscreen blowers, windscreen wipers, rear window heater sometimes. So that's probably where the alternator fails, it could maybe keep the battery charged if I wasn't having to use those.

Since I've purchased a new battery I can't see that the problem can be anything else now. The car has been starting fine but since I've been monitoring the last few days and seeing the voltage slowly decrease I'm pretty sure I'm going to have an issue soon.

I'll give it another test tomorrow and give some accurate figures with certain electrics on.

Paul
 
Hi all,

Mainly just to help anyone searching the forums I'll give an update.

Have replaced the alternator after realising that the voltages being less than 14.0v with most electrics off really wasn't high enough. I think actually with just some electrics on the voltages were goin as low as and even sometimes lower than 12.5v.

With new alternator the voltages are constantly over 14 volts with engine on, I think it was around 14.3 / 14.4, dropping to at worst just under 14 volts with literally everything on, and that's only at idle rpm.

I think I can conclude that with it being winter here and me having to drive with the lights constantly on and needing at least occasionally wipers / fan blowers etc, the old alternator just couldn't keep up and consequently it was draining my battery over the course of 1 - 2 weeks resulting eventually in failure to start.

The battery I replaced seems to have no issues, charged it indoors and it's retained 12.7 volts for a couple of weeks sat in the cupboard.

I would recommend anyone having issues to carefully check voltages with voltmeter and make sure the alternator can keep up when electrics are being used.

Cheers,

Paul
 
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