Cold air continuously coming through floor vents

TJBob

TJ Enthusiast
Joined
Feb 17, 2019
Messages
165
Location
South central Indiana
Having an issue with heat. I have cold air continuously coming in through the floor vent. No matter what vent option is selected. Seems to be more prominent on the passenger side. All the vent selectors work and operate as they should. Jeep has good hot heat. Heat even works on the foot option. It’s just not as warm, because of it mixing with the cold air.

I’ve read some threads about some folks having a similar issue. Their Jeep had good heat on one side, (driver/passenger) but cold on the other. A lot of people talking about the blender door being sticky. Could that the issue in my case? Any other thoughts before I start chasing geese?

Edit: 99 TJ 4.0
 
It sounds to me like your blend door may be stuck. Usually this is due to a vacuum leak somewhere in the system. In which case, I always suggest buying a smoke machine to test for vacuum leaks, as doing it without one can prove nearly impossible. Sometimes those leaks are so tiny and hidden that you'll never find them.
 
It's also possible that one of the drain plugs in your floor pan is missing.
 
It's also possible that one of the drain plugs in your floor pan is missing.
I’ll check the drain plugs, but I’m 99% sure it’s coming out of the lower duct. The volume of cold air increases and decreases with the fan speed. While driving and sitting still. Probably should have included that info in the original post. I’m not sure that it matters or not, but the temp control works as well... turn it to cold, cold air blows, same with the hot setting. Everywhere except the floor. Is there a thread on here about the fog machine? Never heard of it, and wouldn’t have a clue how to approach using it.

Edit: smoke machine*
 
I’ll check the drain plugs, but I’m 99% sure it’s coming out of the lower duct. The volume of cold air increases and decreases with the fan speed. While driving and sitting still. Probably should have included that info in the original post. I’m not sure that it matters or not, but the temp control works as well... turn it to cold, cold air blows, same with the hot setting. Everywhere except the floor. Is there a thread on here about the fog machine? Never heard of it, and wouldn’t have a clue how to approach using it.

Edit: smoke machine*

Check this out:

There's a number of them out there such as this one:
https://www.amazon.com/dp/B0746SL9D6/?tag=wranglerorg-20

I'm also fairly certain you can rent these at AutoZone.