electrical fault

[Keith Milligan]

After it rains my Fusion wont start, it acts like the battery is flat, A garage replaced the battery thinking it was at fault but it has done it again with a new battery, The last time it happened it stood for 2 days and when i went to start it it fired straight up. The only light that comes on on the dashboard is the immobilizer light. I think water is getting in somewhere but where do i start looking to sort the problem..

[Keith Milligan]

So after some checking found the rear fog light to be full of water, The whole light cluster  has a printed circuit board type system and the bottom inch would have been under water. Would this cause the car to act like the battery was dead...

[isetta]

can't see it would have any affect if the fog light was not switched on and even if switched on I still doubt it.  I did read your original post earlier today but had no ideas on the cause to mention to you.