A/C and Heater only blow through defroster

[Dino's 99XJ]

Do you think it is just the canister under or a vacuum leak going on? Is there an easy way to diagnose of fix this issue? No matter where I set the HVAC unit it only blows up high. thanks!

 

[mako my day]

Quick search will bring up many threads. Usually just a vacuum leak at the front bumper canister, or on the manifold.

 

[Frank Z]

Check your vacuum reservoir for a proper connection and look for any disconnected/leaking vacuum lines.

 

[Dino's 99XJ]

all the research just says check for leaks basically, which is obvious. but I was thinking what you guys said, most likely at the canister. I will check it out first and then follow the lines if no luck there. thanks

 

[old_man]

There is a common point of failure where the hard plastic line is routed by the battery.

 

[Dino's 99XJ]

did not realize that, I will definelty look there also. has 152k on it, so I am sure some lines should be replaced anyway at this point.

 

[YELLAHEEP]

There is a common point of failure where the hard plastic line is routed by the battery.

Indeed. Battery corrosion and plastic don't play well together. I've also found that if the corrosion didn't get to that line, it's dry and will develop hairline cracks that you can miss on visual inspection. Best to remove the line to give a good looking over.

 

[Dino's 99XJ]

i will do that. thanks