A/C - Loss Of HVAC Modes, Vacuum Leak

File In Section: 1 - HVAC

Bulletin No.: 73-11-02

Date: March, 1997

Subject:
Loss of HVAC Modes (Route Vacuum Line Inside the Frame Rail)

Models:
1997 Chevrolet Venture
1997 Oldsmobile Silhouette
1997 Pontiac Trans Sport

Condition

Some owners may comment on the loss of HVAC modes. This loss of function will only allow air flow out of the defroster and heater outlets.

Cause

Debris (i.e., snow, ice) may splash up and accumulate on the vacuum line for HVAC system which is located underneath the vehicle on the passenger side. This accumulation will cause excessive weight and possible damage to the line. Damage to this line may cause a vacuum leak and result in the loss of HVAC controls.

Correction

Route the vacuum line inside the frame rail.

Procedure

1. Disconnect line from vacuum canister.

2. Because of two possible designs, select one of the following.

a. Remove line from weld stud clip on the passenger side floor pan.

b. Disengage clips and line from bottom of frame rail and remove clips from line.

3. Route the line rearward through the triangular hole on the forward right side of the frame rail. Exit the line through the square type hole just forward of the vacuum canister and re-attach.

4. Check for leaks and cycle HVAC system modes for proper operation.

Warranty Information

For vehicles repaired under warranty, use:

Labor Labor
Operation Description Time

D1705 Harness, Vacuum Hose - 0.2 hr
R & R or Replace