I can't connect my piwik on SSL

Hello everybody,
this is my first topic on this forum.
I’ve installed piwik on a subdirectory of my website (hosted on siteground.com) with ssl certificate.
The ssl certificate is working well on my website and on piwik (the bar show https in green colour).
On my website is working Wordpress and I installed the Piwik Plugin, I’ve put the tracking code on the plugin and modify the config file to force SSL as instructions, but Piwik don’t work.
I read the other topic on the forum but I didn’t find the same question.
There is someone that can help me? Thank you very much.

Hi there,

What do you mean by this? do you get some error message or some other output?

Thank you for your reply.
Let me explain better, piwik doesn’t track anything.
With Firebug I see error 400 on every page of my worpress site (I’ve installed wp-piwik).
Could you please help me?
Thank you very much.