Battery draining 1.6 61 plate zetec

[Debs1234]

Hi everyone. Really need some help with my 18 year old sons car. The battery light keeps coming on while driving, then the ABS light. He pulls over and switches the engine off and then the car will not restart to the point of no hazard lights or anything. As the battery is driving it looks like he is having a disco as the whole dash starts flashing until it is complete dead. Jump the car and then it drives fine for a day or then same thing happens again. 
had new battery and alternator fitted along with a couple of other bits dues to failing MOT to the tune of £870. He is on an apprenticeship and can’t keep affording to pay out. Any ideas before we take it back to the garage?? Please help   

[Luke4efc]

Check the battery voltages when the engine hasn't run for a few hours, then check it with the engine running and as many electrical accessories on as possible (fan on full, radio switched on, lights etc.). The voltage should be around 14v when you do this, and not drop much when you turn everything on.

[Debs1234]

Hi the battery has 14v when it has been tested. The radio has never worked since he has had it. 

[TomsFocus]

As said over on the other thread, I'd check the thick battery cable for any damage to cause a short.

There's no common Mk7 Fiesta issue that would cause these symptoms as far as I can remember.  (Unlike the cluster soldering on the Focus for example).

It might also be worth unplugging the SmartCharge plug on the alternator and letting it default to the standard 14.4v permanently.  That will at least rule out a SmartCharge fault.

[Debs1234]

Thank you. Is this something we can do ourselves or do I need to get the garage it to do it? Will have a look on good old YouTube and see if we can 

[TomsFocus]

I think you can reach the alternator plug easy enough on the Mk7 to try yourself.  The battery cable runs underneath the battery box though so not possible without a few tools.

[Neb_engineer]

Also it would be a good idea to check the car's off leakage current, disconnect the negative, put an ammeter between the battery negative and the negative cable, wait 10 minutes for the car to turn off, then look at what the amperage is, this will tell u if you have something being a parasitic draw