• Welcome to the new NAXJA Forum! If your password does not work, please use "Forgot your password?" link on the log-in page. Please feel free to reach out to [email protected] if we can provide any assistance.

A/C fan only blows in defrost mode

G

gator_grabber

NAXJA Forum User
Location
Gainesville, FL
A friend has an 88 XJ in which the A/C fan only directs air in the defrost mode. Moving the slider to Max, Norm, Bi-Level, Vent & Defrost makes no difference, all the air enters at the base of the windshield. We replaced the control unit with another that is known to work...no difference. My guess is that a vacuum leak is the culprit, but have no idea where to start the search in a logical manner. Any words of wisdom? :worship:

Thanks!
 
My 2000 did the same thing, ended up being the vacuum like to the vacuum caniter in the front bumber had a crack in it behind the battery.
 
Not a problem. My MJ seems to be missing it's vacuume canister, and when I was searching in an attempt to diagnose it, I spent about a half hour trying to get the correct keywords to find that thread. I'm glad I was able to help.

Pat
 
Did you check the lines that run under the battery tray? I hear that those are quite prone to failure. The other spot you could check is the vacuum cans under the dash. One's on the driver's side sort of above the gas pedal. the other is on the passenger side down and inboard of the glove box area.

It would seem likely that it is a vacuum issue somewhere. I'm still trying to figure it out on my MJ, but it seems that in my case the blower motor is shot, so I'm not putting a lot of effort in to finding mine :)

Pat
 
Ran out of time today. As luck has it, I have an entire under dash air system (with vacuum lines still attached) from a '90 parts Jeep. We'll use this tomorrow as a 'road map' to chase the lines down!
 
Problem solved. Found where unidentified rodent took 2 bites out of the hard vacuum line, just where it enters the fire wall. Here's a tip...try blowing air into the vacuum lines (once isolated from intake) and listen for the leak. Worked like a charm this time! :sunshine:
 
You must log in or register to reply here.

Similar threads

G
Holes in defrost door
Replies
1
Views
1K
N8N_99xj
N
S
98 A/C resurrection
Replies
15
Views
3K
XJlimitedx99
X
M
1992 XJ A/C Air Conditioning Replacement - Parts List
Replies
7
Views
2K
Rob Mayercik
R
S
Climate control vent selection
Replies
3
Views
1K
SurplusFan98
S
S
Chasing a weird vacuum/AC issue
Replies
12
Views
2K
RCP Phx
R
Back
Top