How to Change the Temperature Sending Switch in a Ford Explorerby Dan Ferrell
A hot temperature is good for your Ford Explorer’s engine performance, but a temperature too hot is a warning that there is trouble under the hood. The job of the temperature sending switch or coolant temperature sender in your vehicle is to let you know, through the temperature gauge on the dashboard, when the engine is operating under abnormal temperatures. However, an aged sender unit may fail to detect an overheating engine and may fail to warn you of a major disaster. Avoid this critical situation by replacing the broken temperature-sending unit on your Explorer.
Removing the Coolant Temperature Sender
Park your Ford Explorer in a safe place and open the hood.
Make sure the engine and radiator are cool to avoid severe skin burns.
Locate the coolant temperature sender on your Explorer model. If you have a 2.3L or 2.5L engine, look for it to the left (driver side) and rear of the engine, below the cylinder head (see the Tip section for more information). On the 3.0L, 2.9L, 4.0L (including SOHC) and 5.0L engine models, look for it around the front and top area of the engine, on the intake manifold. The temperature sender resembles a short, brass spark plug with a wider shell.
Detach the ground (black) cable from the battery using a wrench.
Place a drain pan under the Ford Explorer in the area of the temperature sender to catch any coolant that might spill after removing the sender unit.
Loosen the radiator cap to relieve any pressure left in the cooling system.
Unplug the single wire connector from the sender by pulling the L-shaped rubber boot straight up.
Clean the area around the sender unit to prevent any contamination of the cooling system when installing the new unit. Use a clean shop rag.
Unscrew and remove the coolant temperature sender using a wrench or ratchet and socket.
Installing the Coolant Temperature Sender
Coat the threads of the new coolant temperature sender with an electrically conductive sealer.
Screw the new sender unit in place by hand and finger tight.
Tighten the temperature sender using the wrench or ratchet and socket.
Plug the single wire connector onto the new sender unit.
Attach the ground (black) cable to the battery using the wrench.
Add new antifreeze to the cooling system to replace the lost coolant and tighten the radiator cap.
Start the engine of your Explorer and let it reach operating temperature. Check for proper operation of the new sender unit and coolant leaks at the sender unit.
- Ford Explorer, Mazda Navajo, Mercury Mountaineer and Explorer Sport/Sport (Haynes Repair Manual); Jay Storer and John H. Haynes; 2005
- On the 2.3L and 2.5L Ford Explorer engine models, both the coolant temperature sender and oil pressure switch are located in the same area, very close to each other. They look almost identical; even the wiring and connector assembly are similar. However, the temperature sender unit is located below the oil switch.
Things You'll Need
- Drain pan
- Clean shop rag
- Wrench or ratchet and socket
- Electrically conductive sealer
- New antifreeze
Since 2003 Dan Ferrell has contributed general and consumer-oriented news to television and the Web. His work has appeared in Texas, New Mexico and Miami and on various websites. Ferrell is a certified automation and control technician from the Advanced Technology Center in El Paso, Texas.