Cooling fan Relay always faulty

Another problem arise, This happen so many times, The relay cooling fan hot and brunt, so i have to scratch the burnt place and connect it back to the connector base. It ok for a while 4-5 weeks then burn again. SO i change the relay. then burnt again. I don't know what is the real problem. Is that the wiring or the relay or the lose connector or the cooling fan itself? Things that i've done change the relay and tghtimg the connection between the base connector and the relay. 2 is left the wiring and the cooling fan not changed yet. I found this Q&A, I think this would help.

Question: 1999 Ford Taurus V6 3.0 mileage: 65,000. When I put the air-conditioner on it works fine until the condenser heats up at which time the clutch slips. The problem is that the fan under the hood does not come on when the air is turned on. What activates this fan to come on when the air is turned on?

Answer: First, check for 12-volts to the fan motor when the air-conditioning is on. Also, check the wiring for damage and poor ground connections. The fan is controlled by an integrated controller. You may need a cooling fan motor.

May be I will try select this option :- change the cooling fan.

Oxygen Sensor -How does it Works?

This is eg. of the burnt O2 sensor.

Every new car, and most cars produced after 1980, have an oxygen sensor. The sensor is part of the emissions control system and feeds data to the engine management computer. The goal of the sensor is to help the engine run as efficiently as possible and also to produce as few emissions as possible.



A gasoline engine burns gasoline in the presence of oxygen (see How Car Engines Work for complete details). It turns out that there is a particular ratio of air and gasoline that is "perfect," and that ratio is 14.7:1 (different fuels have different perfect ratios -- the ratio depends on the amount of hydrogen and carbon found in a given amount of fuel). If there is less air than this perfect ratio, then there will be fuel left over after combustion. This is called a rich mixture. Rich mixtures are bad because the unburned fuel creates pollution. If there is more air than this perfect ratio, then there is excess oxygen. This is called a lean mixture. A lean mixture tends to produce more nitrogen-oxide pollutants, and, in some cases, it can cause poor performance and even engine damage.

The oxygen sensor is positioned in the exhaust pipe and can detect rich and lean mixtures. The mechanism in most sensors involves a chemical reaction that generates a voltage. The engine's computer looks at the voltage to determine if the mixture is rich or lean, and adjusts the amount of fuel entering the engine accordingly.

The reason why the engine needs the oxygen sensor is because the amount of oxygen that the engine can pull in depends on all sorts of things, such as the altitude, the temperature of the air, the temperature of the engine, the barometric pressure, the load on the engine, etc.

When the oxygen sensor fails, the computer can no longer sense the air/fuel ratio, so it ends up guessing. Your car performs poorly and uses more fuel than it needs to.

Why 'Fuel Saver' in your car supposedly 'save th fuel' don't make any differencee?

Newly car always have computer controlled engine which include of O2 sensors, fuel injection system and so on integrated and calculated to produce the efficiency of the engine, how much fuel to the sparkplug and so on. In some car it called ECU

Fuel saver try to save your fuel consumption, for example the hyrogen producing fuel saver that inject hidrogen+oxygen the the air intake and mix with the petrol to make more combustible engine which in turn make fuel lesser for longer distance. Saves fuel. Less fuel more kilometers.

In my opinion and from what i've read. The ECU or computer seeing this phenomena differently. Whenever external substances added and make the engine leaner with less fuel, the computer keep trying to correct the situation by adding more fuel to make engine idle to at the previous state. Because the computer sees this situation as abnormal and try to correct it. So instead of it saves fuel now it consume more fuel.

So after a long time many claims that the fuel saver don't works anymore. It just funtion well at the beginning, it smoothes the engine when idle for example. it saves fuel but now back to previus state.

After reading some articles in internet, There is a guy which uses the HHO technique as fuel saver. He also introduce a method/technique to fools the O2 sensor. The method is to send the false signal to the O2 sensor that eventhough the hho gas injected to the combustion chamber the engine is fine no demand for more fuel, the engine is normal. So by this way the 'fuel saver works. It saves gas.

The method is to troduce simple electronic circuit to the O2 sensor in the middle before it reach to the ECU/computer box.

More info:


EFIE Circuit


In the past, fuel savers would not work when applied to fuel systems with oxygen sensor feedback circuits. These systems were designed to prevent efficient combustion!

Modern fuel systems use an oxygen sensor to maintain a constant air-fuel ratio of the engine. Increasing the combustion efficiency of the engine increases the percentage of oxygen in the exhaust because the engine uses less fuel for the same volume of air and more oxygen is free because the engine produces less carbon monoxide and oxides of Nitrogen.

The increased oxygen content in the exhaust is read by the computer to be a lean mixture in the engine. As a result, the computer then adds extra fuel to bring the pollution back to normal. In other words, when the computer sees extra oxygen in the exhaust, it sends enough fuel to maintain a 14.7 parts air to 1 part fuel ratio. When the computer sees less oxygen in the exhaust, it backs off on the fuel to maintain a 14.7 to 1 fuel ratio. The EFIE's function is to modify the oxygen sensor's output-signal by adding a floating voltage; so the computer will not see the extra oxygen and fight your fuel saver by adding extra fuel.

May this info might help.

Why My Radiator Water Keeps Dropping?

There are several reasons of engine cooling system failure.

Common Engine Cooling Problems:

Let's look at the common problems cars have with the cooling system.

Broken tubing. Hoses and tubing wear out and leak coolant fluid. Once the coolant has left the system it can no longer cool the engine and therefore the engine will over heat.


Broken fan belt. The water pump is driven by the engine through a fan belt. If this belt breaks the water pump can not turn and coolant will not be pushed through the car engine. This will also lead to the engine overheating.


Damaged radiator cap. The radiator cap is designed to hold a certain pressure in the coolant system. Most caps hold 8 - 12 PSI. This pressure raises the point in which the coolant will boil and maintains a good, stable system. If your cap does not hold enough pressure, then the car engine could overheat on hot days since the system never becomes pressurised.


Water pump failure. Most commonly you will hear a horrible screeching noise and will be able to see engine coolant leaking from the front of the pump or underneath the car. Often there are early signs of trouble with small spots of coolant under the car after being parked overnight and a strong coolant odor whilst you are driving.


Head gasket. Do you have large amounts of white smoke flowing out of your exhaust? Then you could have a problem with your head gasket. The head gasket seals the cylinder head to the engine block and also seals the coolant passages. When this gasket fails coolant can enter the cylinder and it will be turned to vapor as the engine fires. Head gaskets most often fail after the engine has overheated in the past. When very hot, the cylinder head can warp and prevent the engine head gasket from sealing properly.

My car have water radiator level keep falling after a 3-4 day drive. And need to top up after 3-4 days. In the past i have car breakdown due to cooling fan malfunction. So engine become overheating and make me to stop the car in the middle of the road. After repaired (cooling fan replaced) the water level of my radiator keep falling after few days. I have checked no water leakage and my mechanics also found no leakage.

I think the head gasket is the problem as it suit what happen to my car in the past. And I never replaced the head gasket yet.