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Auxiliary Heater Element Relay

Relays and Modules › Relays and Modules - HVAC
Unified entry — merged from multiple cross-listed pages in the original manual.
Procedures
Cabin Heater Relay - Removal3 steps
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  1. Disconnect and isolate the negative battery cable.
  2. Open the cover (1) of the diesel accessory fuse/relay block (2) located at the right front of the engine compartment.
  3. Remove the positive temperature coefficient (PTC) relays as necessary from the fuse/relay block.
Cabin Heater Relay - Installation4 steps
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  1. Position the positive temperature coefficient (PTC) relays as necessary into the proper receptacle of the diesel accessory fuse/relay block (2) located at the right front of the engine compartment.
  2. Align the PTC relay terminals with the terminal cavities in the fuse/relay block and push down firmly on each relay until the terminals are fully seated.
  3. Close the cover (1) of the diesel accessory fuse/relay block.
  4. Reconnect the negative battery cable.
Auxiliary Heater Element Relay: Description and Operationreference
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DESCRIPTION Two relays (1) are used for the electric positive temperature coefficient (PTC) heater system when equipped with the 2.8L diesel engine. The relays are International Standards Organization (ISO)-type relays. Relays conforming to the ISO specifications have common physical dimensions, current capacities, terminal functions and patterns (2). The PTC relays are electromechanical devices that switch fused battery current directly to the heating elements of the PTC heater unit. The PTC relays are energized by control circuits of the totally integrated power module (TIPM). The two PTC relays are located in the diesel accessory fuse/relay block at the right front corner of the engine compartment.