General Electrical problems

[Splash9]

I've got an F reg Tipo which has had electrical problems lately.
The car itself has always been a superb starter and runner but recently after a few miles or so (it can be 3 miles or 30) the battery will start to drain. The dash, being digital, will dim and eventually the radio will fade too low to hear. At this stage the engine will also become lumpy and lose power as it struggles to fire sufficiently. Once the engine is running it will usually continue until switched off but should you try to restart it the battery will appear totally dead. Should I try to start it a few hours later or the next day it is quite likely to burst into life again. As a result I have taken to carrying around a spare fully charged battery which will always start everything up again but this is obviously less than ideal.

The dashboard also dims whenever the lights or any other high load item ie heated rear window, gets turned on.

I have changed the alternator twice for exchange scrap items but the same fault persists, so the symptoms suggest something other than the battery or alternator. An earthing fault appears most likely but which, where and how do I isolate it ??????

please, please help ... ((

Pete

 

[custard]

check the main earth strap/s from the engine to the bodywork,give em a tug to make sure there good connections even if they look okay

The Fiat Cinquecento
Fun While It Runs

 

[Splash9]

Ok .. I've had a good TUG .. taken off the strap to the block which also bolts on just below the battery to the bodywork and I've given everything a good going over with a wire brush. I've measured the resistance between the earth terminal and the block & also to the body and in both cases it shows as being 0.00 ohms ... but even with the third change of alternator it still only shows as kicking out 12.86 volts.

HELP !!!!!!

 

[custard]

have you checked the earth strap(if its there)fron the alternator to the head ,it usually connects across the mounting bracket and if not fit one anyway,i can feel for you as i had a car that would randomly melt a lternators and i never found the problem but a nice lorry driver remodelled the back end for me

The Fiat Cinquecento
Fun While It Runs

 

[Splash9]

there isn't actually a strap attached to the alternator. It just appears to earth straight onto the block. I'm more than happy to add an extra strap in but I've measured the resistance from the alternator housing back to the battery and it shows up as 0 ohms too.

Do you still have the address of the friendly lorry driver ??

Splash