Auto Repair Q&A



Cooling System










Auto Repair Products

2002 dodge ram 1500 no heat replaced radiator,theromostat,

feel the heater hoses -

feel the heater hoses - should be very hot if flowing properly - did you flush the system when you changed the radiator? heater core may be plugged up and not real easy to change.

water pump! many of these

water pump! many of these have plastic impellers on the pump that go bad. If you have "some" heat going down the road and it gets colder when idling, remove and inspect the pump

Search Result Case Number

Search Result
Case Number 999926529
Vehicle Issue Poor heater system performance or function.;Applies to most DaimlerChrysler models. Heater system performance or function is not normal.
System or Component Abnormal Behavior / Function;Customer Concern (No DTCs);Group 24 - Climate Control - Heating / Air Conditioning,Heater;Yes - Intermittent,Yes - Continuously
Recommendation See list of possible causes provided. Diagnose and repair as required. GROUP [A]: COOLANT DELIVERY SYSTEM: ITEM 1): COOLANT LEVEL: Check engine coolant level. Add Mopar Engine Coolant as required. ITEM 2): THERMOSTAT: Engine thermostat may be stuck open preventing normal engine operating temp. ITEM 3): WATER PUMP: Engine cooling system water pump impeller may be damaged or loose preventing normal coolant flow to the heater core. May cause low heat output when engine is idling. ITEM 4): ACCESSORY DRIVE BELT: Check for accessory drive belt tension below specification. Adjust drive belt as required. ITEM 5): HEATER CORE: Check heater core for restriction / blockage. ITEM 6): HEATER CORE SUPPLY HOSES: Check heater system hoses for restriction / blockage / tight bends. GROUP [B]: AIR DISTRIBUTION SYSTEM: ITEM 1): AIR DUCTS RESTRICTED OR BLOCKED: Check all climate control system ducts for possible restriction or blockage. ITEM 2): BLEND DOOR: Check for normal blend air door operation. Check blend door actuator / gear drive / linkage / rod arms / pivot shaft / stops. ITEM 3): VACUUM SUPPLY TO CLIMATE CONTROL SYSTEM: Verify engine vacuum is normal. Check climate control system vacuum supply reservoir / check valves / tubing. Check vacuum tubes for fluid / oil contamination. Repair any vacuum leak detected. NOTE: If vehicle is normally operated at high altitude suggest install secondary vacuum reservoir to ensure adequate climate control system vacuum supply. GROUP [C]: ELECTRICAL: ITEM 1): SYSTEM CONTROL / CIRCUIT WIRING: See list provided below of electrical components that are used in the heater system. Refer to applicable circuit wiring diagram for details. Many of the components listed can be checked with the DRB diagnostic tool. Verify proper operation of any sensor / switch / control component that is related to heater system operation. Suggest use test jumper wires to bypass suspect circuit wiring and to manually check operation of specific components such as the blower motor. Diagnose and repair as required. SYSTEM COMPONENT LIST: [A]: HVAC control head / control panel. [B]: Temp select switch. [C]: Passenger compartment temp sensor / in-car temp sensor. [D]: Infrared temp sensor used on some models with automatic temp control (ATC). [D]: Circuit wiring / connectors / power feed and ground connections. Check for poor pin connections and chafed wiring harness (rub through). [E]: Blower motor / blower motor power module / blower motor relay / blower motor resistor. ITEM 2): AFTERMARKET ADD-ON EQUIPMENT: Check for aftermarket add-on equipment or device that may cause the condition being diagnosed. END OF PROCEDURE

Modification Date 01/18/05 11:41 AM