[dali555]

Started up my TJ the other morning and put the front window defroster on and blasted it on high to clear it.... Went for about 2 seconds then I heard a flap thump and all the air came out the 2 small slits that defrost the side glass.... I stop everything and then put it on again on low and it was coming out the top again.... moved it to the second location on the motor dial and it worked for a couple of seconds then I heard that thump again and lost my windshield defrost.....
Anyone ever have this happen?
Is something just loose or am I f#%$ed!
Thanx,
Marc

[The Danimal]

I'm having kind of the same problem but have yet to see if anyone has posted up what the problem could be. I can run my defroster at any speed but after approximatley 5 seconds I get the thump and then no air to the window.

[dali555]

Anyone?????

[Combatsylvania]

vacuum leak maybe? Its vacuum actuators that set how the air flows.. when you first flop it, it has anough vacuum in the canister to pull it, if its leaking it runs out of vacuum and pulls itself out of whack..

im talking out my a$$ here, I have never seen or fixed this problem.. but I can picture it in my head..

[TravMsns]

I have this exact same problem and have no clue what it is. I can only run my defrost on low or else I hear the thump of a flapper and no air coming out the defrost. Surely someone out there has had it and fixed it. Anyone?

[Dogman]

Okay, this is a very common issue. If you're hearing a thump, it's the doors in the box flapping shut because you have a broken actuator arm. There is a master thread here and I'll dig it up for you.

Also, I suggest not changing the air flow with the fan on anything but the lowest setting - that will snap the cheesy little arms in no time.

[Dogman]

Here you go: http://jeepforum.com/forum/showthread.php?t=66176&highlight=broken+heater

[TravMsns]

Thank you! That's exactly what I was looking for.

[dali555]

Me too THANX!

[dali555]

Well with my crappy luck I put the screw in and the head snapped so now I have the screw stuck in the snapped end and it is useless.... Anyone find a place that sells these crappy little arms? All the stealerships can't get them and want me to buy the whole assembly for $270.00! I tried some local junkyards here in CT with no avail....
I need help!
Marc

[dali555]

For anyone else on the forum... I just found a site that sells just the little plastic arm for the defroster duct. It was $20 for the part but that is much better than $270 for a new heater box assembly! Here is the link to the site....

https://www.discountjeepparts.com/index.php?osCsid=de0f0675709291adf6845a03ca949c83

Hope this helps anyone else on the forum with this problem!
Marc