Chevrolet Repair: 1994 GMC Suburban, gmc suburban, air cond

Question
i have a 1994 GMC Suburban there is a sloshing noise coming from behind the glove box, what is located on the cabin side of the firewall.
Thankyou

Answer
Hi Brett... there is a drain back there that could be plugged. it is for draining the water that may come in from the cold air duct just in fron of the windshield... check on the firewall under the hood just below the heater/ air cond box, there should be a fitted hose there. try cleaning it out... hope this helps