To find it, you'll need to:
1. Identify your specific Jeep model: (e.g., Grand Cherokee Laredo, Wrangler TJ, Cherokee XJ)
2. Consult a repair manual: A repair manual specific to your year and model will show you exactly where the heater control valve is located. You can find these online (often as PDFs) or at auto parts stores.
3. Search online forums: Search online forums specific to your Jeep model and year (e.g., "1999 Jeep Grand Cherokee heater control valve location"). Other owners may have posted pictures or descriptions of its location.
Without knowing the specific Jeep model, any answer would be unreliable and could lead to wasted time searching in the wrong place.