The fan should spin at max RPM if any temp sensor is not detected, as a failsafe. Is something interfering with the fan mechanically? The SSD should draw less power than a regular HDD, so I am wondering if this might be mechanical and not electrical.
You can run the unit without reassembling it to see if a cable or the SSD housing is interfering. I can't image the SSD housing is causing a problem, but you never know.