Air defrost only

Hopper

Hopper

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Noticed the my 99 automatic 4.0 air only blows out the defrost vents. Looked here and found out how to inspect the lines. From the T on passenger firewall I tracked it to driver side and all looked good. Followed to under battery box and all looked good. The 3rd line that goes up is cut. From the T that line is about 4" and connects to nothing. Im assuming this line should go through the firewall and connect to the actuator?
Couple questions

1. if I dont fix right away should I tape it or cap it so it is air tight.
2. Would not fixing it cause driving issues?
3. Am correct the dash is comming out when I do decide to fix it?
Thanks

Sorry it wont let me attach the photo even after I resize to 20%. Technology
 
Hopper said:
Noticed the my 99 automatic 4.0 air only blows out the defrost vents. Looked here and found out how to inspect the lines. From the T on passenger firewall I tracked it to driver side and all looked good. Followed to under battery box and all looked good. The 3rd line that goes up is cut. From the T that line is about 4" and connects to nothing. Im assuming this line should go through the firewall and connect to the actuator?
Couple questions

1. if I dont fix right away should I tape it or cap it so it is air tight.
2. Would not fixing it cause driving issues?
3. Am correct the dash is comming out when I do decide to fix it?
Thanks

Sorry it wont let me attach the photo even after I resize to 20%. Technology
Click to expand...

There should be a vac line entering the firewall thru the foam seal where the heater hoses enter. That is the line to the control system, find the end and connect to the T at the firewall.
 
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TJ4Jim said:
There should be a vac line entering the firewall thru the foam seal where the heater hoses enter. That is the line to the control system, find the end and connect to the T at the firewall.
Click to expand...

Thanks. I was able to get my hand behind the glove and find the other end. There definitely isn't enough to feed it to the T. I may if I contorsion enough be able to slide some tubing over it and feed it through the firewall to the T.
Until then should I plug or tape off the broken tube at the T so it will hold vacuum?
 
Hopper said:
Thanks. I was able to get my hand behind the glove and find the other end. There definitely isn't enough to feed it to the T. I may if I contorsion enough be able to slide some tubing over it and feed it through the firewall to the T.
Until then should I plug or tape off the broken tube at the T so it will hold vacuum?
Click to expand...

Yeah, that's the best option.
 
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tr21triton said:
If you found both ends just splice it with some rubber tubing and be done with it .
Click to expand...

Cause I'm gonna have to squeeze my hand up behind the dash. Then probably have to put the tubing over it one handed since I can't easily get both hands on it. All while my back is jackknifed over the tub. Or take out the seat and lay on the floor that way. Ill get it but it wont be easy to reach and Im gonna have to be in the mood for that kinda frustration.
 
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Hopper said:
Cause I'm gonna have to squeeze my hand up behind the dash. Then probably have to put the tubing over it one handed since I can't easily get both hands on it. All while my back is jackknifed over the tub. Or take out the seat and lay on the floor that way. Ill get it but it wont be easy to reach and Im gonna have to be in the mood for that kinda frustration.
Click to expand...

Just suck it up and get er done !
 
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Full disclosure...this is for an 05 HVAC system. I know there are some differences between the older and newer TJs, but the routing of the vacuum line should be similar.

Best I can see from my photos, the vacuum line travels from the engine side of the firewall over the HVAC case to the vacuum harness that's accessible from behind the glovebox. You should be able to fish a wire/coat hanger from the engine side, over the HVAC box to the passenger compartment. Aim for the fuse block or somewhere close. If you get ahold of it from the passenger compartment side, fish it back to the engine side with a hose attached and make the connections to the engine side vacuum and the harness. On my 05, looking to the left of the fuse block, I can see where the vacuum line goes through the firewall. Loosen the screws on the fuse box and you might be able to get a better look. If nothing else, its worth a try. Here are a few photos for visual reference...


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