Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
SYS.OK|MANUAL.DB● LIVE
HOMESERVICE MANUALSJEEP1991CHEROKEE 2WD L4-150 2.5L VIN P MFIREPAIR AND DIAGNOSISHEATING AND AIR CONDITIONINGTESTING AND INSPECTIONCOMPONENT TESTS AND GENERAL DIAGNOSTICSA/C PERFORMANCE TESTING
1991 Jeep Cherokee 2WD L4-150 2.5L VIN P MFI
A/C Performance Testing
1991 Jeep Cherokee 2WD L4-150 2.5L VIN P MFISECTION A/C Performance Testing
Fig. 7 Temperature Pressure Relationship Chart:
1. Connect pressure gauge and manifold assembly to the compressor service valves and close both valves on gauge and manifold assembly.
2. Open both service valves to the mid-position.
3. Operate the system with engine at 1500 RPM and controls set for full cooling but not to the "Max" or "Cold" detent.
4. Insert a thermometer in the discharge air outlet and observe the air discharge temperature, then compare pressure and temperature to chart.
RENDER: 1.0x
NO RELATED
Recommended Tools & Savings
Use the Manual With the Right Hardware
Pair factory procedures with proven DIY tools so the instructions are easier to execute.
Affiliate disclosure: We may earn a commission at no extra cost to you.
When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.