• Welcome Visitor! Please take a few seconds and Register for our forum. Even if you don't want to post, you can still 'Like' and react to posts.

Defrost/Vent / vacuum issues?


dangeranger88

New Member
Joined
Aug 12, 2008
Messages
179
Reaction score
0
Points
0
Location
york pa
Vehicle Year
1999
Make / Model
Ford
Engine Size
3.0L FF
Transmission
Automatic
I'm having this issue with my 1999 Ranger XLT with the 3.0 -- When I am going up a hill at 3000RPM or higher, the vents will start blowing through the defrost. Its very annoying! Does anyone have any ideas about this? I assume its some sort of vacuum issue...I also know that this model had vacuum-operated auto hubs which I replaced with manual lockouts, would that maybe have anything to do with it, even though i did that almost two years ago and this issue only recently started happening.

Also, I'm not sure if this is related or not but while idle, the AC compressor clicks on and off in a rhythmic fashion. Bothers me a bit. AC works great however. Any suggestions? Thanks guys

Oh and if it may help the ranger's got 33" tires and 4.10 gears in the rear.
 


Big Jim M

New Member
Joined
Apr 18, 2008
Messages
2,728
Reaction score
30
Points
0
Age
86
Location
Austin
Vehicle Year
2002
Make / Model
Ford
Engine Size
4.0
Transmission
Manual
Yep!

I'm having this issue with my 1999 Ranger XLT with the 3.0 -- When I am going up a hill at 3000RPM or higher, the vents will start blowing through the defrost. Its very annoying! Does anyone have any ideas about this? I assume its some sort of vacuum issue...I also know that this model had vacuum-operated auto hubs which I replaced with manual lockouts, would that maybe have anything to do with it, even though i did that almost two years ago and this issue only recently started happening.

Also, I'm not sure if this is related or not but while idle, the AC compressor clicks on and off in a rhythmic fashion. Bothers me a bit. AC works great however. Any suggestions? Thanks guys

Oh and if it may help the ranger's got 33" tires and 4.10 gears in the rear.
Sounds like when you disconnected the vac operated hubs you encouraged a vac leak..
There is a cannister that KEEPS vac in it to make sure the hubs and the A/C doors have vac when the engine isn't providing it..
So I'd be taking a good look at the canister and all vac lines.
The FAIL-SAFE of the heater/AC is to go to defrost when vac failure occurs.
Big JIm:hottubfun::wub:
 

hondaxr650

New Member
Joined
May 21, 2010
Messages
640
Reaction score
4
Points
0
Location
Tacoma, WA
Vehicle Year
1997
Make / Model
Ford
Engine Size
4.0
Transmission
Automatic
You probably have a vacuum leak. The heater defaults to defrost when vacuum is lost to the controls. Lots of folks have found their vacuum reservoirs cracked. It looks like a black ball and is down in the rf corner of the engine compartment.

Looks like Big Jim beat me to it!
 
Last edited:

dangeranger88

New Member
Joined
Aug 12, 2008
Messages
179
Reaction score
0
Points
0
Location
york pa
Vehicle Year
1999
Make / Model
Ford
Engine Size
3.0L FF
Transmission
Automatic
Okay thanks guys, that is very helpful I will check things out. Where can I look for the vac lines that go to the hubs? I don't remember ever seeing them! Maybe I can just plug them up?
 

triumphrider-1

Active Member
Joined
Nov 18, 2007
Messages
2,023
Reaction score
14
Points
38
Location
Port Huron, MI
Vehicle Year
2011
Make / Model
Ford F150
Engine Size
3.7L
Transmission
Automatic
The vacuum lines attach to a metal line on the top of the spindle. If you've put manual hubs on, just pop the lines off and plug them up at the T (located near passenger frame rail and front cross member).

--OOPS. Knuckle, not spindle.
 
Last edited:

Sponsored Ad


Sponsored Ad

Staff online

Member & Vendor Upgrades

For a small yearly donation, you can support this forum and receive a 'Supporting Member' banner, or become a 'Supporting Vendor' and promote your products here. Click the banner to find out how.

Truck of The Month


Shran
April Truck of The Month

Recently Featured

Want to see your truck here? Share your photos and details in the forum.

Follow TRS On Instagram

TRS Events

25th Anniversary Sponsors

Check Out The TRS Store


Sponsored Ad


Sponsored Ad

Sponsored Ad


Amazon Deals

Top