1. Power Supply:
* Fuse/Relay: Check the fuse and relay specifically for the cooling fan(s). The 1992 Caravan likely has separate circuits for the fans (one for low speed, one for high speed, or one for each fan). Consult your owner's manual or a wiring diagram to locate the correct fuses and relays. Visually inspect them; a blown fuse will be visibly broken. A bad relay may need to be tested with a multimeter.
* Wiring: Inspect all wiring connected to the fans, relays, and fuses. Look for broken wires, corrosion, loose connections, or chafing against metal. Pay close attention to the connectors at the fan motors themselves.
* Fan Switch/Control Module: The switch in your vehicle's interior (or the control module, depending on the model) may be faulty. If you have multiple fan speeds, try them all to see if there's a short somewhere within the system.
* Temperature Sensor: The system relies on a coolant temperature sensor to trigger the fans when the engine overheats. A faulty sensor may prevent the fans from turning on, even though the engine is overheating. This would usually cause the fans to *never* turn on. You'll need to diagnose with an OBDII scanner or a multimeter to test this sensor's resistance at different temperatures (carefully, as the coolant is hot!).
2. Fan Motor Installation:
* Ground Connection: Ensure both fan motors have a good ground connection. A poor ground can prevent them from working.
* Wiring Connection: Double-check that all wiring connections to the fan motors are secure and correctly wired. A wiring diagram is essential here. A reversed wire can burn out the motor (but you replaced them, so this is less likely but still possible if installed incorrectly).
* Motor Itself (again): While you've replaced them, it's possible (though less likely) you received faulty replacement motors. Though extremely rare, it's worth considering if you've exhausted all other options.
3. Additional Considerations:
* AC System: If the AC compressor is running and causing problems, this could indirectly impact fan operation.
* Wiring Harness: A damaged section within the wiring harness itself may be causing the problem.
How to Proceed:
1. Start with the simplest things: fuses and relays.
2. Use a wiring diagram: This is crucial for tracing the electrical circuits and finding potential problems. You can often find these online or in a repair manual.
3. Use a multimeter: A multimeter can test voltage, continuity, and resistance to help pinpoint the fault. If you're not comfortable using one, take your Caravan to a mechanic.
4. Consider professional help: If you're not comfortable working with car electrics, take your vehicle to a qualified mechanic. Continuing to drive with non-functioning cooling fans could severely damage your engine.
Overheating can cause significant engine damage, so it's essential to resolve this issue quickly. Don't attempt to drive the vehicle without functional cooling fans unless you are certain they aren't needed (e.g., short test drive).
