Section H
SECTION H - REPAIR PROCEDURETrinary Switch - Check/renew & Install Extension Hose
1. Use a calibrated digital multi-meter set to read DC voltage (Mv range).
2. Reconnect the battery ground cable if vehicle is not in group 8.
3. Turn the ignition switch to the auxiliary position. Select low fan speed. Select A/C and MAX on the A/C control panel. Ensure that the compressor clutch has engaged, then proceed as follows.
4. Locate the compressor clutch relay (FE 47), on the passenger side bulkhead. Connect the red probe of the DVOM to the compressor clutch relay terminal 85 carrying the Blue/Black (U/B) cable, and connect the black probe to a good earth stud connection and note the measurement.
5. If the voltage measurement is 60 Mv DC or less, no further action is required with the trinary switch.
If the voltage measurement is GREATER than 60 Mv DC, the trinary switch will require replacement using the following procedure.
6. If the vehicle is in group 8, note the customers preset radio stations and remove the battery cover. Disconnect the battery ground cable.
7. Recover the refrigerant from the system. Ensure that it is COMPLETELY discharged. Follow the procedures defined in the XJ6 Service Manual number 4; section 82 and the instructions provided with your R134A refrigerant recovery equipment.
8. If the voltage measurement taken previously was greater than 60 Mv DC then change the trinary switch at this time.
Ensure that the system is completely discharged. Disconnect the harness multi-plug (FE 16) on the trinary switch fly lead. Install a new trinary switch (Part No. LMB 7657AA). Item A, Fig. 1. Use the appropriate hand tools.
9. Disconnect the harness multi-plug on the slow fan pressure switch. Using the appropriate handtools, loosen and remove the slow fan pressure switch. Item B, Fig.1. Remove and discard the pressure switch "0" ring.
10. Lubricate the new "0" ring (Part No. KSG 108116) supplied in the kit and carefully fit the "0" ring to the adaptor (Part No. MMB 7375AA). Item D, Fig.1.
NOTE:
Use only approved oil.
11. Fit and tighten the adaptor into the refrigerant hose manifold. (Item C, Fig.1). DO NOT EXCEED THE RECOMMENDED TORQUE SPECIFICATION. Refer to the Torque Chart.
NOTE:
Use extreme caution when installing the adaptor due to the fragile nature of the adaptor threads.
12. Install and tighten the extension hose (Part No. MMB 7374AA), to the adaptor. Items D & E, Fig. 1. DO NOT EXCEED THE RECOMMENDED TORQUE SPECIFICATION. Refer to the Torque Chart. FIG. 2
NOTE:
Use extreme caution when installing the extension hose to the adaptor due to the fragile nature of the adaptor threads. When tightening the hose to the adaptor, an open ended wrench MUST be used to prevent the 3daptor from turning. See Fig 2.
13. Lubricate the new "0" ring (Part No. KSG 108116) supplied and carefully fit the "0" ring to the slow fan pressure switch, see Item B, Fig.1. Use only approved oil.
14. Fit and tighten the slow fan pressure switch (Item B, Fig.1) to the extension hose (Item E,Fig.1). DO NOT EXCEED THE RECOMMENDED TORQUE SPECIFICATION. Refer to the Torque Chart.
15. Position the extension hose / slow fan pressure switch against the corrugated harness tubing at the bulkhead. Secure the pressure switch to the tubing as shown. Use the tie strap provided (Part No. ADU 9028). See Item F, Fig.l.
16. Route the slow fan pressure switch fly lead (part of engine harness) as shown. See Item G, Fig. 1.
17. Release the engine harness bulkhead securing clip, see Item H, Fig.l. Route the slow fan pressure switch harness through the clip and close the clip.
18. Reconnect the slow fan pressure switch multi-plug (FE 7). Position the harness against the corrugated tubing and secure using the tie straps provided (Part No. ADU 9028). See Item J, Fig. 1.
19. Evacuate and recharge the A/C system. Leak check the system to ensure that all refrigerant hose connections are correctly sealed.