The heater quits working on 2008 Dodge Grand Caravan

Sometimes the heater works only a few seconds and other times the air is cool immediately. What could be the problem. On old cars a thermostat replacement would solve this problem. I don't know about newer cars.

Get Your Car Fixed at a RepairPal Certified Shop.
We certify shops based on expertise, quality work, and verified customer reviews
2 answers
I advise you to have your vehicle inspected by your local dealership. This is how complex your system is:

CAUTION: Do not exchange A/C Heater Controls from vehicle to vehicle. Software versions differ between models and model years. Installing an A/C Heater Control with software that is incompatible for a given vehicle can result in either improper or failed HVAC system operation.
NOTE: Always inspect the IOD fuse prior to diagnosing any automatic temperature control (ATC) system concerns. Make sure the fuse is functional and fully seated into the terminals of the Totally Integrated Power Module (TIPM) located in the engine compartment.

The A/C-heater control communicates on the Controller Area Network (CAN) IHS bus and is fully addressable with a scan tool.

The A/C-heater control's primary means of fault detection is through active and stored Diagnostic Trouble Codes (DTCs). Active DTCs are those which currently exist in the system. The condition causing the fault must be repaired in order to clear this type of DTC. Stored DTCs are those which occurred in the system since the A/C-heater control received the last clear diagnostic info message. All DTCs must be read with a scan tool (Refer to 28 - DTC-Based Diagnostics/HVAC - Diagnosis and Testing) .

The A/C-heater control's secondary means of fault detection is through system tests. These tests include the HVAC System Test, the A/C Cooldown Test, the Actuator Calibration Function, and for MTC Systems, the Actuator DTC Detection Test. Refer to System Tests in this Section for a detailed description of each test.
The HVAC System Test provides a starting point in the diagnostic process by identifying the appropriate system test to perform when diagnosing a given condition or DTC. It also provides a means for testing the entire HVAC system by utilizing the A/C-heater control's On-Board System Tests. The On-Board System Tests can also assist in diagnosing stored DTCs

I think you may have a problem in the heater control system. Get it checked out by a Dodge specialist.
If you want to find a specialist, here's a directory link for you: