Heater Unit
PART 1REMOVAL
WARNING:
- ALLOW THE SUPPLEMENTAL HEATER TO COOL BEFORE PERFORMING A COMPONENT INSPECTION/REPAIR OR REPLACEMENT. FAILURE TO FOLLOW THESE INSTRUCTIONS MAY RESULT IN PERSONAL INJURY.
- ALLOW THE EXHAUST SYSTEM TO COOL BEFORE PERFORMING A COMPONENT INSPECTION/REPAIR OR REPLACEMENT. FAILURE TO FOLLOW THESE INSTRUCTION MAY RESULT IN PERSONAL INJURY.
1. Raise and support the vehicle. Take note of the location of the flexible exhaust tube section.
2. Drain the engine cooling system.
3. Carefully open one hose to the underbody tube assembly and drain the remaining coolant. A salvage hose is a good idea to control the residual coolant, as flow will occur from both the heater and the hose and tube assemblies.
4. Remove the second hose from the underbody hose and tube assembly.
5. Loosen the hose and tube assembly from the toe-board cross member at two locations.
6. Disconnect the electrical connector from the body harness near the toe-board cross member and rail.
7. Remove the wiring harness from the toe-board cross member.
8. Open the fuel filler cap. Disconnect the rubber fuel hose between the body tube assembly and the fuel pump nipple at the body tube joint. A minimal amount of fuel may flow from the open port.
NOTE: Utilize an approved fuel storage container to catch any residual fuel.
9. Loosen the two fasteners at the rail. Take care to notice that the exhaust tube bracket tab is on top of the heater bracket and that there are two spacer washers installed between the rubber grommets.
10. Remove the heater exhaust tube flex section from the exhaust tube by loosening the bolt of the clamp assembly. Remove the hose from the exhaust tube.Removal of the rail tube assembly may aid in this service operation.
11. Remove seat hex nut at the heater mounting flange to cross member.
12. Loosen the remaining fasteners which mount the exhaust tube assembly to the vehicle.
a. Install a suitable cabin heater support device under the cabin heater and secure the cabin heater to the device.
13. Loosen the remaining three fasteners to the cross members.
14. Remove the loosened fasteners that support the heater while supporting the weight of the heater.
15. Swing the unit mounting bracket from between the exhaust bracket and rail mounting location. Drain any residual coolant from the heater unit.
16. Lower the cabin heater and remove from the supporting device and place on a suitable work area.
INSTALLATION
1. Install the unit mounting bracket between the exhaust bracket and the rail mounting location.
2. Install the fasteners that support the heater while supporting the weight of the heater.
3. Install the three fasteners to the cross members. Tighten the M6 fasteners to 7 N.m (62 in. lbs.).
4. Position the two spacer washers between the body and the rubber grommets for the two mounting points on the rail.
5. Tighten the remaining M6 fasteners to 7 N.m (62 in. lbs.) and the M8 fasteners to 23 N.m (17 ft. lbs.) which mount the exhaust tube assembly to the vehicle.
6. Install the seat hex nut at the heater mounting flange to the cross members. Tighten the nut to 60 N.m (44 ft. lbs.)
7. Install the heater exhaust tube flex section to the exhaust tube by tightening the M6 bolt of the clamp assembly. Install the hose to the exhaust tube.
8. Tighten the two M8 fasteners at the rail to 23 N.m (17 ft. lbs.). Taking care so that the exhaust tube bracket tab is on the top of the heater bracket.
9. Install the wiring harness.
10. Tighten the hose and tube assembly to the toe-board cross member at two locations.
11. Install the second hose to the underbody hose and tube assembly.
12. Connect the rubber fuel hose between the body tube assembly and the fuel pump nipple at the body tube joint. Close the fuel fill cap.
13. Remove the heater unit support device from under the vehicle.
14. Lower the vehicle.
15. Fill the engine cooling system.
16. Verify function of the cabin heater.
PART 2
REMOVAL
1. Raise and support the vehicle while taking note of the location of the flexible exhaust tube section.
2. Unplug the wire harness connector from vehicle wiring harness to cabin heater harness.
3. Unplug the wire harness connector from cabin heater harness to dosing pump connector.
4. Unplug the two wire harness connectors from cabin heater harness to cabin heater controller connectors.
5. Remove two wiring harness connectors from underbody.
6. Remove two wiring harness connectors from cabin heater shield.
7. Carefully route the cabin heater harness to the left side between the cabin heater unit and the cabin heater shield.
INSTALLATION
1. Carefully route the cabin heater harness from the left side of the cabin heater between the cabin heater unit and the cabin heater shield.
2. Install the two wiring harness retaining connectors to the cabin heater shield.
3. Route the wiring harness along the underside of the vehicle and install the two wiring harness retaining connectors.
4. Plug the two connectors from the cabin heater harness to the cabin heater controller.
5. Plug the connector to the cabin heater harness to the dosing pump connector.
6. Plug the connector from the vehicle wiring harness to the cabin heater harness.
7. Lower the vehicle.
8. Verify function of the cabin heater.