Mercury Marine has been long known for its reliable, high-quality products. However, their most celebrated product is their outboard motor, famous for its exceptional durability and low maintenance.
The thing with outboard motors is, the risk of overheating is always there, especially when you use the boat for long hours under the scorching sun. A simple temperature sensor will prevent that and put your mind at ease.
If you want to know everything about Mercury outboard temperature sensor location and how to install it, here’s what you need to know.
How to Install Mercury Outboard Temperature Sensor
A temperature sensor is essential to have on your outboard so you know if your engine is about to overheat. If you don’t know what it looks like, it’s basically an analog meter that moves according to the motor’s temperature.
There are some digital sensors, but analog ones are more common. If you want to install a sensor or a gauge on your motor to protect it from overheating accidents, here are the necessary steps to do it.
Step 1: Buy the Temperature Sensor
The first thing you should do is buy the temperature sensor with its kits. To do so, you need to make sure it matches the sender unit on your engine.
The temperature sender unit is a tiny device on your engine, meant for protection. It’s usually placed on the engine block, and it keeps monitoring the temperature of the coolant. You’ll want to make sure your sensor of choice is compatible with it.
Step 2: Prepare the Wiring
Most likely, the temperature sensor you’ll buy will come with its own wiring. But in case that doesn’t happen, you need to prepare the necessary wires. You’ll need 18-AWG terminal wires and ¼-inch female blade terminals.
Keep in mind that you may need more if your temperature sensor has lighting. You’ll need to read the installation requirements written on the pack.
Step 3: Prepare the Engine for Installation
To install the temperature sensor, first, remove the head bolts on top of the motor. Then, you’ll need to make a hole on the outboard motor that’ll fit the size of the temperature sensor. You can make a 2 1/16-inch hole—or according to the sensor’s size—then take the sensor out for installation.
Step 4: Attach the Wiring
You need to attach the sensor’s wirings to get temperature readings. To do so, read the instructions on the pack. First, you should find a knob on the sensor labeled ‘S,’ referring to signal. Connect your wire to it, then close it using a nut and lock enclosure.
Grab the other end of the wire, and attach it to the temperature sending unit on your outboard motor. This wire will be responsible for transferring the temperature signal, therefore, responsible for the accurate reading. If you’re not sure you connected it correctly, it’s better to ask a professional.
After you’re done with it, grab the other cable and attach one end to a 12VDC circuit and the other end to the ignition knob on the sensor. You’ll find it labeled ‘I.’
Step 5: Do Some Final Tweaks
After you’re done connecting the cables, you need to connect the ends of the electrical base, so you’re sure the sensor will work when you attach it. To do so, connect the sensor to the G key, and lock it with a nut. The sensor’s package will likely include the needed tools.
After you’re done, it’s time to finalize the installment. Start by connecting the blade terminal aligning it with the positive side of the lighting circuit. Then, tighten the nuts and make sure everything is in its place, and you’re done.
Safety Precautions for Installing a Mercury Outboard Temperature Sensor
When installing a temperature sensor on your Mercury Outboard, you should follow some safety precautions. For starters, make sure you disconnect the battery before doing anything. On top of that, check the temperature before starting.
Before finalizing the installation, make sure all the nuts are tight enough, especially on the back clamp.
Lastly, read all the instructions on the sensor’s pack and follow them closely. If you haven’t done this before, it’s better to consult a professional or get help from a friend.
What Are Mercury Outboards?
Mercury’s outboard engines are incredibly popular among boat owners. The American company managed to build one hell of a reputation after more than 80 years in the market.
The engines are best known for their durability and low maintenance, which pushes more people to buy them every year. Mercury makes its engines from various steel alloys. They’re all resistant to corrosion and designed to handle saltwater and its wear and tear.
All the engines are also topped off with Iriditie sealers and Electro Deposition primers for protection.
Needless to say, if you own a Mercury outboard, it’s going to last for a long time. The average life expectancy is 2000–3000 hours, depending on how often you use it and whether you maintain it.
How to Tell If Your Mercury Outboard Overheats?
If your Mercury outboard motor is overheating, you’ll know in an instant. For one, the temperature gauge will go into the red zone, which means the engine is already overheating. Secondly, you’ll feel the engine losing its power or acting erratically.
Some engines also refuse to start up when they’re overheated. Instead, they’ll likely stay shut until they cool down.
Outboard motors usually overheat because of a bad radiator or a leak in the cooling system. The first thing you should do is check for leaks, then see the radiator and its fan. Otherwise, the water pump may be malfunctioning.
The Takeaway
Now that you know the Mercury outboard temperature sensor location, you should be able to install it correctly. However, before attempting to do so, make sure you buy the right one that matches your engine. Read the instructions before proceeding, and make sure you have all the required tools.
It’s also better to ask for a professional’s help whenever you need it.