Stewart,

The small diagram you posted shows the tensioner relief going down, or "clockwise". That doesn't seem right, even for a dual setup.

It also shows what appears to be an A/C compressor clutch below the tensioner. That would be for a gasser, not a diesel, wouldn't it?

I'd lift up on the breaker bar to relieve belt tension if the actual belt routing looks like the full diagrams given.

Pop