Weird Temperature problem

Hi,
I built a CNC controller with a torroidal transformer at the power
supply end. Everything works fine (almost). The Problem I have is when
the garage is cold (I have the setup in my garage) around 57F or less
I keep blowing the AC fuse to the transformer. I normally run fine
with a 3A fuse but when cold it blows a 6A fuse as soon as the power
switch is flipped.

To debug I disconnected the transformer from the diode caps etc.. so
it was just open and still I kept blowing the fuse. Now I heat up the
transformer with a hair dryer and after it is warm I turn it ON and it
does not even blow up a 1A fuse. So on warmer days (>65F) when I was
using the power supply it was working fine…

My question is has anyone seen this kind of problem and do you have
any recommendations for a solution.

Thanks
Kim