Hi!

Does anyone know what could be causing my battery to drain on my FiatPunto 60 SX T Reg - 1999 to the point where even my interior light wont come on!
I am now on my second battery in as many months, I have not fitted anything new on the car. I had a feeling that it could have been a faulty alarm that was installed by the prev owner over 3 years ago, so I got rid of it at the weekend, took the batt out and put it on charge overnight. Next day I put the batt back, and everything was fine! Started first time with no problems at all.
Next day, went out and surprise surprise, it was dead again!
The only other thing I can think it might be is the stereo. I have noticed that the stereo will stay on, music n all even with the ignition off and the key out. I have another car, Honda Civic and the stereo goes off when ignition is off. This has been the case on all cars I have had in the past as well.

Should the stereo stay on even with the ignition off ??? If not does anyone know how to fix this, I noticed on another thread that someone was saying the Fiat wiring does not match the iso connection wires, could this be something to do with it ???

I have also bee told that it could be a bad ground causing the drain. What the hell does that mean?? lol!

:bang:

There're a number of things you could look at.

1) Is the alternator OK? Put a multimeter across the battery with the engine off and you should see about 11.5-12.5 Volts. With engine idling you should see around 13 Volts. If you rev the engine a bit then you should see around 14-14.5 Volts.

2) Are any courtesy lights staying on? The boot light can be a common cause of battery drain.

3) You're right, the stereo wiring doesn't seem to conform to ISO. I had to adapt the wiring for my wife's car. You need to look at the manual for your stereo and see what connection requires a switched live (this is a wire that is only live when the ignition is "on"). I can't remember what one I used.

4) If a "live" wire is shorting out (it's been damaged and is earthing itself) then you may get some current drain. Look at the wiring going to the tailgate. Because the wiring gets flexed a lot, it can break over time and cause hassle.

If you don't have the manual for your stereo, you can probably find it on the web somewhere.

Thanks 4 the reply!

I have looked at the wiring diagram for the stereo and the switched live (red) seems to be connected to the same wire coming from the wiring loom on the car. Im sure it is something to do with the stereo now. I did think it was the alarm, but hey U cant always be right!! lol!

Thanks 4 the help, I will keep trying!

My Wife's Punto has a Kenwood with a removeable faceplate, the previous owner just pressed the button to release the plate, thereby "killing" the stereo. Obviously not an expert like moi [].

LoL! I dunno, thats women 4 ya!

Take out the fuse of the suspect device (having first checked that it is served through a fused feed!)

You need to check and see which circuit is draining your power, also you could have an internal Battery fault ( unlikely you say it is new ) or I once had an alternator with an internal fault that pulled 2 amps ! This was easily traced one frosty morning when i saw steam coming off the bonnet !

You need to disconnect the battery Earth connector and then place an ammeter between the battery Neg terminal and the disconnected Earth wire. You shoud only see a minimal current drain somewhere about 0.035 amps which will be your clock and maybe the odd Microprocesser here and there on modern cars. I would then start pulling fuses to see which one has an effect on your ammeter.

It might also be an idea to plug the same ammeter into your cigarette lighter socket using a power plug adaptor and monitor the cars voltage as you drive along, you may find with a faulty alternator that it goes bad after a while when it has heated up and done a bit of work.

If you have a Multi meter and a bit of time Electrical faults are usually easy to trace as long as you are methodical in your approach to them, good luck .

Of the 4 Fiats that I've owned I found that the Radio will still come on even with the key out , although they are normally set to auto turn off after 20 minutes. This was always a guide guide for moaning at the wife whilst waiting out side Tesco's. "You've been in there for 3 radio turn on's , what where you doing woman, making the shopping !"

hi there

i assume that you can turn your stereo off manually and you arnt leaving it on ? if so then i doubt its your stereo, but you can alter teh wiring to make them go off with ignition i did so on my 2001 punto just had to swap 2 wire and it goes off now.

i also dont think its your alternator as you say it went flat ina day, if it was alternator it would take a fews days in my opinoin before it was so flat interior light dint work.

my money is on some sort of short that is draining battery.