Help with a few issues.

[wildman4x4]

So I am working on the daughters manche and have an issue that has me going huh? I fixed the aftermarket stereo not working right. The PO had the constant 12V wire wired to switched power also so you'd lose all your settings every time it was turned off. So now I am on to fixing the HVAC. I checked the vacuum line coming into the cabin and it has vacuum but I only get air out of the defrost. Doesn't matter what position it is in it still only blows out defrost. So where do I go from here? Looking for any advice.

[Nofeartoys]

Some info off the top of my head and looking at a early xj heater box diagram. First do you hear a vac leak in dash area? Second need to check operation of door actuator for defrost door. According to xj diagram on left side of heater box. Maybe just kicked actuator rod off of the door. I know on dodge trucks. Defrost mode is default if vac lost

https://imgur.com/a/K7zCH Is vac diagram I found. ( blue and green go to defrost door)

If cable driven actuator move mode slider on control head and watch door actuator to if cable system working

[Eagle]

The usual cause of this is a vacuum leak in the line beneath the battery tray, to the vacuum reservoir "blimp" that's mounted behind the bumper on the passenger side.

[cruiser54]

[wildman4x4]

Because of the funky Rough Country bumper the reservoir blimp is up on the wheel well now. I know for sure the line going into the blimp is not leaking.

 

No I do not hear a vacuum leak under the dash any where. I guess I'll have to get my vacuum tester out and test all the diaphragms to make sure they all work and all the doors work. I'll keep everyone posted on what I come up with.

[mikekaz1]

If you have the ability to. Try a smoke test and see if you get any leaks

[64 Cheyenne]

If you have the ability to. Try a smoke test and see if you get any leaks

 

If you don't have the ability (smoke/smoker), get one of your smoker buddies to do it. Meaning remove a vacuum line blow smoke in it, see where it leaks out.

[ParadiseMJ]

... I know for sure the line going into the blimp is not leaking...

 

No I do not hear a vacuum leak under the dash any where. I guess I'll have to get my vacuum tester out and test all the diaphragms to make sure they all work and all the doors work. I'll keep everyone posted on what I come up with.

 

There the vacuum supply line going IN to the blimp, and should be a smaller line coming OUT.  Two in and two out if you have the football style and it's properly teed off.  The diagram is for a post Renix vacuum system (being that the cruise is on the passenger fender).  The more vac lines, the more possibility for leaks. 

 

All of the lines on the left (passenger) side of the engine affect only the cruise, heater valve and HVAC door operation and have little if anything to do with the "running" of the engine, unless you have a huge leak in the SOURCE line from the manifold.

 

You should find a black and pink line coming out of the firewall. One goes to the heater control valve, the other goes into the dash.  If you have a line disconnected or leaking to or between any of those, even if you vacuum TO the dash, it could be compromised by a small leak in the cruise line or anywhere in the larger SOURCE line coming from the manifold.

 

The smoke test will find even the tiniest leak.  Cigar smoke works best IMO.

 

If you find leaks, you're better off replacing the lines instead of taping, splicing or just repairing them.  Bulk vac line is cheap, cheap. Just sayin".