A/C heater door open???

[crashfirepm53]

My rear A/C seems to blow cold as compared to the front.How do I check to see if the heater door is open?Is it located on the Pass. side.Thanks,
Scott

 

[ugly_blazer]

I'm not sure how to check the heater door, but a shut-off valve installed in the heater hose is a quick fix.