1. Check the Fuses: Start with the easiest. Your owner's manual will show you the fuse box location and which fuses are related to the HVAC system (heater, blower motor). Check for blown fuses and replace any that are.
2. Blower Motor: The most common culprit. The blower motor itself might be faulty. This requires accessing the blower motor (usually under the dashboard, potentially requiring some disassembly) and checking for power at the motor's connector using a multimeter. If there's no power, the problem lies upstream. If there is power but the motor doesn't spin, the motor needs replacement.
3. Blower Motor Resistor: This controls the fan speeds. A faulty resistor can prevent the blower from working at any speed or only at the highest speed. It's usually located near the blower motor and is relatively easy to access and test/replace.
4. HVAC Control Head: The unit that controls fan speed, temperature, and airflow direction. A malfunctioning control head can prevent the blower motor from receiving power. This is more complex to diagnose and often requires replacement.
5. Relay: A relay might be controlling power to the blower motor. A bad relay would prevent the motor from receiving power. These are usually located in fuse boxes and can be tested with a multimeter.
6. Wiring: Check all wiring related to the blower motor, resistor, and control head for breaks, corrosion, or loose connections. A visual inspection is crucial.
7. AC Compressor Clutch: If you're trying to use AC, a faulty compressor clutch could indirectly affect blower operation (some systems won't engage the blower if the AC system is under pressure or experiencing a fault). This requires more specialized tools to check.
Troubleshooting Steps (in order):
1. Check the fuses. This is the quickest and easiest step.
2. Test the blower motor for power. If no power, move to step 5 or 6. If power but no spin, replace the blower motor.
3. Check the blower motor resistor. This is often a common problem.
4. Inspect all wiring. Look for damage, corrosion, or loose connections.
5. Test the relevant relay(s).
6. Check the HVAC control head. This is more difficult to diagnose and replace.
7. Check the AC system if applicable.
Important Notes:
* Safety First: Disconnect the battery's negative terminal before working on any electrical components.
* Consult a Repair Manual: A repair manual specific to your 1995 Jeep Grand Cherokee will provide detailed diagrams and instructions.
* Professional Help: If you're not comfortable working on your vehicle's electrical system, it's best to take it to a qualified mechanic.
By systematically checking these components, you should be able to pinpoint the cause of your no-air problem. Remember to test each component individually to isolate the fault.
