Hi, I bought my first car, a VW Polo 9n (2009) in early 2020 - so very much a newbie to cars. I fitted a new radio in July of that year (incorrectly at first, which led to a flat battery from radio being left on, but later sorted it so it turned off when I switched off ignition).

 

It may not be linked but, a month or two later I started experiencing problems with ABS warning light turning on and power steering failing. This was very intermittent and only seemed to happen when driving in traffic, with phone plugged in and radio on etc. Garage immediately said it was the alternator, but no warning light came on for alternator, also no error codes showing up when scanned, the voltage to battery and alternator was good. They said not much point changing alternator as it looks fine when tested. I left it for a while but same thing happened when driving in slow moving traffic (air con, phone and radio all on) and so I thought I should get alternator changed for peace of mind. It was changed and no problems with the car for the next 7 months or so.

 

About a week ago the same problem has started again. Abs light on in traffic, power steering goes and warning lights on. When I pull over and restart the engine I lose the warning lights and regain power steering. Took it to a different garage this time (I've moved), they scanned it and said it was an ABS Pump fault (they checked voltage on battery and alternator and fuses e.t.c). I asked them to take a closer look as i suspected a more intermittent electrical fault and now they are getting a low reading from alternator (under 13.5 watts), when all electrics turned on (fine otherwise). I can't go back to old garage (too far away) for warranty on the alternator that was changed less than a year ago. First step I've been advised by various car mechanics is to change the alternator again as I may have just been unlucky with a dud, but if I do replace it and continue experiencing issues does anyone know where to look? 

 

Would love to know if anyone has experienced similar problems and can suggest some solutions.

Which engine type does the car have?

If you put the key in the ignition and turn it to the position where various warning lights appear, do you see the battery symbol illuminate?

 

it's a 1.2 and no battery symbol. The battery looks pretty new, think it was changed 6 months or so before I got the car.

No batt light at ignition on usually means a blue wire has broken on its way to the alternator.  Find a bracket on the front face of the gearbox, near the starter motor. Find a two-way connector pair with a blue wire going in and out of each half of the pair, see if that blue wire is broken nearby.  The other wire going through that connector pair may also be broken.

 

Edit: Depending on engine code, it might actually be a 14 way connector near the main battery negative earth connection to chassis, pin 3 thereof.

Edited 30 July, 20215 yr by Pete1
Found that connector location may differ for BMD code