Audi A4: Any way to disconnect the alternator?

n30_mkii · 31 Mar 2009 at 17:58

As above I have an Audi A4 2002 TDI, I'm having issues with a drained battery and so I'm just trying to dismiss the alternator drawing back as a cause. Does anyone know of a simple way to disconnect the alternator from charging the battery? Just so I can leave it stood for a couple of days and check the drain. Any advice appreciated!

Dale V · 31 Mar 2009 at 18:02

remove the belt?

n30_mkii · 31 Mar 2009 at 18:06

I didn't mean that sorry, I mean disconnecting it from the battery to make sure it's not gone bad and draining the battery when the engine is switched off.

Matt82 · 31 Mar 2009 at 18:07

take the big thick live lead off the alternator. that goes directly to the battery

ethos · 31 Mar 2009 at 18:09

Have you checked to see what voltage you're getting when the car is running?

Dogbreath · 31 Mar 2009 at 18:30

Matt82 said:
take the big thick live lead off the alternator. that goes directly to the battery

And make sure it's well insulated, otherwise you'll have crispy fried Audi.

Matt82 · 31 Mar 2009 at 18:56

true.. im well paranoid about that sort of thing, including the starter motor one

Firestar_3x · 31 Mar 2009 at 18:59

If you took the neg off i guess it would still earth through the engine block?

n30_mkii · 31 Mar 2009 at 19:22

Voltage when running is over 14v, i'm thinking there might be a diode gone. Whats the best way to insulate the lead?

blueboy2001 · 31 Mar 2009 at 20:12

Whip the alternator off and take it to a rewinds place - they'll be able to test output and the diode on it for you in 2 minutes.

LACKERKNACKER · 31 Mar 2009 at 20:33

Not being funny,but why mess about taking alternator lead off and risking knackering up your electric system if you arc it on to the chassis. My advice would be to look at some other areas first, or get it on a diagnostics to check on voltage etc.

Tinders · 31 Mar 2009 at 20:38

14v, when running is fine, you could alway try an ammeter to see what kind of current drain you have at rest, alternators can 'over volt' the battery, but I dont think I have ever seen one drain a battery.

Its seems to me you are barking up the wrong tree