Notices
1999 - 2003 7.3L Power Stroke Diesel  
Sponsored by:
Sponsored by: DP Tuner

vent control problem

Thread Tools
 
Search this Thread
 
Old May 7, 2009 | 05:12 PM
  #1  
firewood's Avatar
firewood
Thread Starter
|
New User
Joined: Feb 2007
Posts: 11
Likes: 0
vent control problem

01 diesel. blower only flows air thru defrost vents. can manually stroke valve to flow air to feet.air pump under hood runs until i unplug line and cap is there a fuse which activates a relay that iam missing
 
Reply
Old May 7, 2009 | 05:28 PM
  #2  
megawatt00's Avatar
megawatt00
Hotshot
Joined: Jan 2008
Posts: 13,144
Likes: 11
From: Rochdale MA
Club FTE Gold Member
You have a vac leak. Chances are it is in the lines that are going to the ESOF. With a vac leak the heat automatically defaults to defrost.
 
Reply
Old May 7, 2009 | 05:43 PM
  #3  
zx250's Avatar
zx250
Of the next Riffraff East
Joined: Oct 2004
Posts: 8,679
Likes: 2
From: Concord NC
Club FTE Gold Member
Originally Posted by firewood
......air pump under hood runs until i unplug line and cap is there a fuse which activates a relay that iam missing
That air pump is actually a vacuum pump and if it's runs all the time, then Jim's right and you have a leak. The ESOF should only leak when you try to use 4x4. If it leaks all the time, then you may have a bad pump, or the line going to the HVAC contols may be leaking.
 
Reply
Old May 7, 2009 | 06:25 PM
  #4  
MR5x5's Avatar
MR5x5
Senior User
Joined: Mar 2007
Posts: 473
Likes: 3
From: Issaquah, WA
The vac system has two subsystems it supports, the ESOF (4x4) and vent systems. You need to isolate which part of the system has the leak. First thing to do is pull the line off the vac pump and cover it with your finger to make sure the vac pump pulls a vac and turns itself off. Reconnect if working.

Next - Isolate the ESOF system. I have personally experienced a failed ESOF ctrl solenoid that resulted in the exact symptoms you are discribing. The solenoid is located just above the fender well. Follow the lines off the vac canister to it. Disconnect and plug the vac line going to the solenoid. This will effectively remove the ESOF system from consideration. If the pump turns off you've identified the offending subsystem.

If the problem persists you need to start following lines back into the vent ctrl system..never been into that stuff before...
 
Reply
Old May 7, 2009 | 06:28 PM
  #5  
PaysonPSD's Avatar
PaysonPSD
Post Fiend
Joined: Nov 2007
Posts: 9,549
Likes: 14
From: Payson, AZ
See this post from 05-01. CLICK HERE
 
Reply




All times are GMT -5. The time now is 07:00 AM.

story-0
This Hennessey Takes the Expedition Tremor's Off-Roading Capability to the Next Level

Slideshow: The VelociRaptor Expedition gains a lift, upgraded suspension, Brembo brakes, and trail-ready equipment while retaining the stock 440-horsepower EcoBoost V6.

By Verdad Gallardo | 2026-06-12 11:01:55


VIEW MORE
story-1
Top 10 Fords at 2026 Carlisle Ford Nationals

Slideshow: Top 10 Fords at 2026 Ford Nationals

By Joe Kucinski | 2026-06-09 11:10:08


VIEW MORE
story-2
3 Best / 3 Worst Parts of Modern Ford Ownership

Based on years of owning multiple modern Ford products.

By Brett Foote | 2026-06-09 10:53:36


VIEW MORE
story-3
10 Amazing Upgrades That Solve Common Ford Truck Owner Headaches

SPONSORED: From muddy boots to rain-soaked cargo, these upgrades address some of the most common frustrations Ford truck owners face every day.

By Pouria Savadkouei | 2026-06-08 18:50:34


VIEW MORE
story-4
Every 2026 Ford Engine Explained

Here's everything you need to know about every Ford engine available for the 2026 model year.

By Brett Foote | 2026-06-05 12:58:01


VIEW MORE
story-5
10 Ugly Ford Trucks That We Still Kinda Love

Slideshow: 10 ugly Ford trucks that we still kinda love.

By Joe Kucinski | 2026-06-03 09:51:16


VIEW MORE
story-6
10 Things Every Truck Owner NEEDS (2026 Edition)

Slideshow: the best gifts for dads & grads

By Michael S. Palmer | 2026-06-03 15:43:58


VIEW MORE
story-7
Rezvani's Latest Post-Apocalyptic Monster Is a Ford F-150 Raptor Underneath

Slideshow: Called the Fortress, the 850-horsepower pickup combines Raptor underpinnings with military-inspired features, survival equipment, and a starting price of $285,000.

By Verdad Gallardo | 2026-06-03 11:38:36


VIEW MORE
story-8
Top 10 Most Expensive Ford Trucks Ever Sold on Bring a Trailer

Slideshow: 10 most expensive Ford trucks ever sold on Bring a Trailer.

By Joe Kucinski | 2026-05-27 16:24:34


VIEW MORE
story-9
2027 Ford Super Duty Buyer's Guide (Every Model, Engine, & Package)

Here's everything that has changed for the latest model year.

By Brett Foote | 2026-05-27 16:17:28


VIEW MORE