Heater stopped blowing after cooling swap

I recently converted my 87 Mj to an open cooling system when the radiator was punctured, the problem I am having now is that the heater function stopped blowing. I can hurn all the other functions to hot- a/c, vent, or defrost and it blows hot, but no air comes out when i switch it to heat. When i do turn it on I can hear it click on and hear some air blowing uder the dash just not from the vents. Prior to the swap everything worked fine, and the A/C will still blow ice cold. Anybody ever had this problem after a cooling swap? and yes i did swap in the control valve as well.

Sounds like the vent door or actuator wonked up. The doors are vacuum controlled. Since you are getting heat, the cooling system change seems OK. Since the other positions work, sounds like there's not a vacuum supply issue. Here's the schem from an 88 XJ. Not sure if your's will be the same but it's all I got.