Alternator or Battery?

[sgtbash]

Hi Guys,

2003 BMW 318i 2.0 with 110k on the clock.

Occasionally, my headlights (while on), glow much brighter than they should for a few seconds whilst driving, at the same time i get static from my radio.

I used the hidden test menu and saw that when the ignition is off, the battery runs as 12 V (normal) when idling/driving at 14V (normal) but occasionally runs at 18V for a few seconds (while I get static from my radio and the headlights glow very bright (its blown a few bulbs!)

Today the battery light lit red for a few seconds whilst driving and disappeared - this is the first time its done this, and I'm now wanting to get it sorted.

So, does this seem like the alternator or battery at fault? (The battery is BMW branded, so im not sure if its the original or not!)

[BFG TERRANO]

Voltage regulator on the alternator gone. You will fry something soon if you don't sort it.

[sgtbash]

BFG TERRANO said:

Voltage regulator on the alternator gone. You will fry something soon if you don't sort it.

Brilliant, thanks for the help!