A/C - Condensate Leakage Into Passenger Compartment
86ford18 Article No. 86-9-14A/C CONDENSATE LEAKS INTO PASSENGER COMPARTMENT - VEHICLES BUILT PRIOR TO MARCH 1986
LIGHT TRUCK 1975-86 ECONOLINE
When a vehicle is operated under conditions of extremely high humidity with the Function Selector Lever in the "NORM A/C" position and the blower switch in "HI", some evaporator condensate, instead of draining out of the vehicle, is being blown through the ducts and registers and into the passenger compartment.
Condensate from the evaporator core exceeds the amount which can be drawn off through the drain tube in the evaporator case. As a result, the excess condensate can be pulled away from the drain tube and picked up in the air stream created by the blower motor. It is then expelled through the A/C registers.
To correct the condition, one or more of the following service procedures should be initiated in the sequence listed. They are to be initiated on a customer complaint basis. Vehicles built prior to March, 1984 will continue to be serviced, as required, by all of the procedures covered in TSB 85-11-16 in addition to the procedures provided in this article. Complaints requiring service on vehicles built from March, 1984 to March, 1986 will be handled by following the sequence of procedures in this article.
NOTE: Operation of the blower at a lower speed than HI will allow accumulated condensate to drain out the drain tube. Therefore, operation of the blower below HI where possible, or periodic reduction of the blower speed from HI, will significantly reduce moisture accumulation. Also, when comfort will allow, operation of the air conditioner in MAX A/C rather than NORM A/C will reduce condensate accumulation by reducing the humidity entering the vehicle.
SERVICE PROCEDURE:
1. The sealing and leak checking procedures previously published in TSB 85-11-16, dated 6/3/85, must have already been performed, or should now be performed before proceeding with the added service operations covered in this article.
2. Replace the evaporator check valve and drain tube assembly (including the 90~ formed drain tube and check valve) with a new check valve and drain tube assembly.
3. If replacement of the evaporator drain tube assembly does not correct the condensate leak, add a separate drain hole in the blower housing as outlined under "Addition of Drain to Blower, Housing".
4. If the condition still persists, install a locally fabricated moisture coalescer screen as outlined under "Addition of Coalescer Screen to Evaporator Assembly".
Sealing and Leak Checking Per TSB 85-11-16
1. Using TSB 85-11-16 as a guide, confirm that the sealing operations described have been effectively accomplished.
2. If sealing is missing, apply it to the surfaces indicated in the TSB.
Figure 7:
Replacement of Evaporator Condensate Drain Tube Assembly - Vehicles Built From March, 1984 to March, 1986 Only (Refer to Figure 7)
1. Remove battery.
2. Pull the check valve drain tube assembly (includes 90~ formed hose and check valve) from the barbed end of the plastic drain tube projecting inboard from the bottom of the evaporator housing.
3. Remove the plastic evaporator drain tube and seal attached to the bottom of the evaporator housing by removing the two attaching screws with a 5/16 inch socket. Discard the drain tube parts and keep the screws.
4. Using a new seal, attach the new plastic drain tube to the bottom of the evaporator drain housing, using two No. 10-16 x .5 hex washer head screws (42367-S2) and two No. 10 spring nuts (Figure 7). No. 10-12 x .5 screws (42127-S2) may be used as an option to screws 42367-S2.
5. Push the new straight check valve drain hose onto the barbed end of the plastic drain tube with the check valve pointing straight down, Prior to installation, ensure that the check valve disc is free to move and check airflow. Conduct the check by blowing and drawing air through the hose.
Figure 8:
Figure 9:
Addition of Drain to Blower Housing (Refer to Figures 8 and 9).
Figure 7:
Adding a drain to the blower housing must be performed only after (or in conjunction with) procedures for sealing of the housing and flanges as outlined in TSB 85-11-16 have been completed and the new straight check valve drain tube shown in Figure 7 has been installed. Failure to eliminate or minimize condensate carryover by following the procedures outlined in TSB 85-11-16 will result in exposing the blower motor to excessive amounts of water which will adversely affect motor life.
1. If equipped with an EEC IV system module in front of blower housing, remove the module cover and dash flange attaching screws and lay the module aside.
2. Remove the blower motor and resistor connections from the blower scroll cover.
3. Remove the blower scroll cover (7 screws) and blower motor (4 screws) from the blower housing (push/pull blower motor wire grommet toward inside of evaporator housing).
Figure 9:
4. Drill a 1/4 inch hole through the lowest corner of the blower housing, as shown in Figure 9.
5. Fabricate an eyelet from 1/4 inch tubing approximately 1 inch long. Insert the eyelet from the inside of the housing and seal around it completely with silicone sealer, or equivalent.
6. Drill a 3/8 inch hole through the dash panel 1 inch to the left of the EEC IV dash panel grommet if the EEC IV system is used. Drill it through the dash plug in the grommet hole if the EEC IV system is not used.
7. Attach a 1/4 inch ID by 8 inches long rubber hose to the eyelet and route it through the hole in the dash or dash plug. Seal the hose to the dash opening or dash plug, as applicable, with silicone sealer, or equivalent.
8. Reassemble the blower, blower scroll, and electrical connections and check for proper blower operation as described in the applicable Shop Manual. Be sure the blower motor wire grommet is pulled into the hole in housing.
Addition of Coalescer Screen to Evaporator Assembly
The coalescer screen provides a barrier and collecting surface for water droplets which are expelled from the evaporator core. The "U" shaped configuration in the direction of the airflow allows water to flow along the screen surface toward the edges of the blend door frame and downward to the bottom of the evaporator housing.
Figure 8:
1. If equipped with an EEC IV system module in front of blower housing, remove the module cover and dash flange attaching screws and lay the module aside. (Figure 8)
2. Remove the blower motor and resistor connections from the blower scroll cover. (Figure 8)
3. Remove blower scroll cover (7 screws) and blower motor (4 screws) from the blower housing (push/ pull blower motor wire grommet toward inside of evaporator housing). (Figure 8)
Figure 10:
4. Fabricate the screen from a piece of 6-1/2 inch by 12-1/2 inch aluminum window screen, as shown in Figure 10.
Figure 11:
5. Compress the "U" cross-section of screen slightly and push the screen through the blower opening and A/C side of blend door frame opening with "U" facing upwards. Once past the blend door frame opening, stand screen upright and pull edges toward the back side of the blend door frame and hold it against the edge of the evaporator core and heater core with sealer (or equivalent) as shown in Figure 11.
6. Check the temperature blend door for full travel and adjust it, if necessary, as described in the applicable Shop Manual.
7. Reassemble the blower, blower scroll, and electrical connections and check for proper blower operation as described in the applicable Shop Manual. Be sure the blower motor wire grommet is pulled into the hole in the housing.
PART NUMBER PART NAME CLASS
E6UZ-19858-A A/C Kit BG
OTHER APPLICABLE ARTICLES: 85-11-16
WARRANTY STATUS: Reimbursable within the provisions of the Warranty and Policy Manual.
OPERATION: SP19858A86
TIME: 0.5 Hr. - Replacement of Evaporator Condensate Drain Tube Assembly
OPERATION: SP19858B86
TIME: 0.9 Hr. - Addition of Drain to Blower Housing and Addition of Coalescer Screen to Evaporator Assembly DLR. CODING: Basic Part No. 19858 - Code: 79