Battery discharging overnight

[tomocr]

I know therem are various reasons for this.  Battery knacked, something left on, diodes in alternator knacked but I was just wondering if there is a common fault to this with the MK2 GTi?  I am going to recharge the battery but leave it out of the car and see if it holds a charge overnight.  Hopefully, it will discharge itself and I can get away with a new battery.  If it holds a charge then either my diodes are knacked (which would exlplain why my electrics cut out whilst driving), or there is a short circuit somwhere in the car.  While I'm at it, does anyone know where I can get a cheap battery?

[16v Matt]

GSF for the battery mate, think I payed under 30 notes.  2 year gauantee as well.

[Mr Blue]

check the boot. the light may be on due to a faulty switch.

[tomocr]

LOL, that was the first place I checked.  I checked online for a battery, £30 seems the normal however I need it tomorrow so will have to buy local, why do Halfrauds sell theirs at £60-£70!!!    Robbing t***s!!!  Well, the battery is current-ly on charge.  I'll get it full, leave it overnight then chuck it in the car to see if it has held it's charge.  Fingers crossed.

[Agreeable Slick]

Replace the regulator on the alternator.

[tomocr]

Which part is that then?  I have heard that you can get a replacement diode pack?  Is this the same thing and how do I go about doing it?

[Agreeable Slick]

Where the cables connect it is on that side, will undo by releasing two screws on it. Easy to replace and only cost a few quid.

[tomocr]

Excellent, I am waiting on the battery charging now.  The plan is to take it to the local parts shop, the guy said he can put it on a deep discharge machine to tell if the battery is knacked.  If it is okay, I think I will take the regulator route if it is that cheap (heck, he might have one in stock).

[tomocr]

Back again.  Could someone do me a favour.  Could someone check to see if they have current from the negative terminal of the battery to the B+ terminal of the alternator with the igntion off and key out?  Or maybe someone with electrics knowledge could tell me if this is right?  I put a multimeter from the - terminal of the battery to the B+ of the alternator and got 10v.