How to Replace Temperature Sending Gauge Switch
The engine is where power to run the vehicle is being generated, and this is done by burning fuel within it. But the engine fails to convert in to power all of the heat that is generated through the combustion process. This fact puts your vehicle's powerhouse in peril because of its susceptibility to overheating. To counter that, your engine has two temperature sending switches or units. One is to keep track of the temperature and the other of the oil's pressure. But they can also fail in time. How would you then deal with faulty temperature sending gauge switch?
Difficulty Level: Moderate
What you'll need:
Step 1: Park your car in a safe level place. Your garage could probably be the perfect place. If the location is a little inclined, secure the vehicle with wheel blocks on all four wheels at the portion facing down.
Step 2: Ask someone to assist you at the wheel. You will need an eye on the dashboard devices, while you work on the engine.
Step 3: Before touching anything under the hood, make sure that the engine as well as the other heat-generating devices have cooled down already. Open the hood to help make heat dissipation faster.
Step 4: Find the temperature sending units. They are housed in the engine block, one in the water jacket and another in the oil passage.
Step 5: Identify the problematic temperature sending gauge switch. Ask your assistant to turn on the ignition. And then, unscrew the sending gauge one at a time. Take note which gauge is faulty.
Step 6: Now, inspect the temperature gauge. You do that by disconnecting the wire at the sending unit, and then, shorting it for five seconds.
Step 7: Check the oil pressure gauge. This is done by shorting its two wires to one another. Make sure that your assistant sees whether the needle swings to high end. If it does, the gauge is working fine. Other gauges may work the other way around, so check your car manual.
Step 8: Also check the warning light system by grounding its wire on the engine block. Note if the light turns on. If it does, the said system is working just fine as well.
Step 9: If both the oil pressure gauge and the warning light systems are okay, the temperature sending unit could be problematic. To find out of its real condition, you have to unscrew it from the engine block in order to be tested.
Step 10: Set your ohmmeter to Low scale before measuring the temperature unit's resistance. Your unit is still in good condition when the measurement reads 50 to 100 ohms while it is cool, or when it reads 2 to 30 ohms when dipped into water that almost reaches the boiling point.
Step 11: Install the new temperature sending unit or switch as necessary. Make sure to use adapter bushings as required. Also ensure that the bulb end is submerged at 5/8-inch, and then tighten with hex nut or corresponding wrench just snugly.