Rear heater question

Hello to all. I have a question regarding my 1995 2500 Burb. My front core is disconnected (when I bought it). The rear is still connected. I am not getting heated air from the rear unit. Any suggestions?
Thank you in advance
Blessings
Chuck aka ulremember

Feel the hoses under the vehicle at the rear- are they both hot? with the front bypassed this may have affected the rear- depending on how it was bypassed.....

Thank you.Will check!
Blessings