Previously i set up load balancer and health check for http protocol and it got set up with no erro. Actually i was setting up load balancer for google cloud cdn. After this google cdn was not working so someone said it must be https so i edited load balancer and converted it to https load balancer. After converting to https , i am facing failed health check. My health check is also in https.
You could curl your HTTP(S) load balancer IP and check the HTTP status codes to understand the actual issue.
curl -I [load balancer IP]
I would like to mention here that HTTP(S) load balancer is a Proxy and requests from clients are terminated at the load balancing layer, then proxied over to your backends. Please find HTTP(S) Load Balancing Concepts documentation link.
Just to clarify here that you can enable Google Cloud CDN for an existing HTTP(S) load balancer backend service or backend bucket or enable it while creating a new one. So, it will work with both HTTP and HTTPS load balancer. Here is the public documentation link on that.
I would recommend posting this type of questions in ServerFault as StackOverflow is for Q&A for professional and enthusiast programmers.