Drove through a big puddle - Alternator F**ked?

[AppleAssassin]

So the other day was driving about Edinburgh with it pissing it down and drove through a rather large puddle at a set of lights, load of steam came up from where it hit hot things - As it does.

Anyway about 200 Metres along the road my battery warning light comes on. I get back to my flat about 5 minutes later and hope that the next day it would have dried out. Anyway took it out for a drive the next day and after about 30 seconds of driving the battery warning light comes back on.

I've tried disconnecting and reconnecting the battery terminals which didn't work. I measured the voltage which was about 12.3v when the engine was off, this was after turning it off and on again while test driving, and it was showing 11.5v while the engine was idling.

I've got the car booked in to the replace the alternator but just wanted to know from you guys if you think my diagnosis is right in that the alternator has gone.

[TheEnd]

It certainly looks like it.
Have you check to make sure the belt is still on?

[AppleAssassin]

TheEnd said:

It certainly looks like it.
Have you check to make sure the belt is still on?

Yeah was the first thing I checked, still nice and tight and hasn't slipped off or anything.

So does that pretty much narrow it down? with the belt being fine and the battery not charging?

[mattyc69]

Try removing the plug on the alternator and giving it a spray with some WD40 might just be some water in there?

[PhillipM]

As above, could be water in the plug, probably where the field wire connects.