Electric Cooling Fan

[hans1977]

Hi,

I've just fitted an electrical cooling fan behind the radiator of my old secondhand car to try to solve the problems i used to have:

1) The engine got very hot (sometimes even started boiling a little) at the traffic lights in a hot day (thus, nearly every day), and to go to Bangkok wasn't really worth even thinking of.

2) The old fan was not in a good condition.

3) The AC wouldn't produce enough cold air at low speed in the day time.

So, i grabbed my pen to plan for a new electrical system. It has got the usual things (such as temperature switch, the actual fan and a relay), as well as an additional relay, an emergency switch and an option selector switch (to select if the fan should run when the AC is on, or not).

The fan is very efficient, and problem number 1 and 2 seams to belong to the past now. I have also tested the usefulness of the option switch and discovered that problem number 3 more or less disappears as i pull the switch.

As a bonus i've also noticed a slight decrease in fuel consumption.

I have found the hard parts of this project to be to find a suitable fan and to find out where and how to fit the temperature switch.

To find a suitable fan i actually had to bring my tools to the shop and disassemble the old system followed by trying to place the fans, one by one, from the shop until i had one that appeared to be the most suitable.

I'm really happy with the system that i've got, and i would recommend anyone with similar problems, to what i had, to have an electrical cooling fan installed.

I would also recommend to plan the job well and buy all the parts before you start if you decide to do it your self. The first part to buy would be the fan, i'd suggest.

You could also do the work in steps, like i did, and fit everything but connect an indicator light instead of the fan to see if everything is working before you've already removed your old system.

Best regards,

Hans

[Lickey]

Hans, well done on your venture, I have a few questions if you dont mind,

Was the original fan electric or belt driven?

Did you replace the thermostat?

Was the cooling system flushed out and new added?

Was the radiator matrix [where the cooling air passes through to cool the coolant} washed out with a pressure washer or blown out with an airline?

That last item is now on a preventative maintainance schedule on big trucks in the UK and is done every 2 months or so.

Rgds, Lickey.

[elkangorito]

Hans, well done on your venture, I have a few questions if you dont mind,

Was the original fan electric or belt driven?

Did you replace the thermostat?

Was the cooling system flushed out and new added?

Was the radiator matrix [where the cooling air passes through to cool the coolant} washed out with a pressure washer or blown out with an airline?

That last item is now on a preventative maintainance schedule on big trucks in the UK and is done every 2 months or so.

Rgds, Lickey.

These are good questions.

Unless the vehicle is a thousand years old, there can be no foreseeable reason why your engine should get "hot" if the cooling system is ok (maintained). If it has not been maintained correctly or has another problem (head gasket?), the problem will come back soon enough.

Also, what do you consider "hot"? How did you measure this "hot" temperature?

[hans1977]

Thanks!

My old system was belt driven. You know the ones with grease in the center?

I don't have a thermostat. I don't think that is necessary in Thailand anyway. They would always be opened anyway, wouldn't they? Or maybe you mean the temperature switch? I did not have one before, but now i have fitted a switch from a different make.

I have recently changed the coolant fluid and the radiator, so i haven't done anything about that when installing the electrical fan.

Best regards,

Hans

Hans, well done on your venture, I have a few questions if you dont mind,

Was the original fan electric or belt driven?

Did you replace the thermostat?

Was the cooling system flushed out and new added?

Was the radiator matrix [where the cooling air passes through to cool the coolant} washed out with a pressure washer or blown out with an airline?

That last item is now on a preventative maintainance schedule on big trucks in the UK and is done every 2 months or so.

Rgds, Lickey.

[hans1977]

I have done everything there is, except changing the belt driven fan, to the old system. The engine got cooler when i replaced the radiator, but it still got too hot at certain times.

My car is just below a thousand years old, i think, but the whole engine and cooling system has been completely looked through before i changed to the electrical fan. I'm quite sure that the old system could not be brought up to the standard of an electrical fan cooled system. Possible it could be changed to become acceptable, but that would still be less than what I've got by this new system, and more expensive as far as i can see now.

I have not measured the temperature in terms of degrees, I've rather watched the temperature meter at cruising speed as well as at the traffic lights and the difference was more than 5 mm on the meter's scale. In addition to this i also noticed the coolant fluid to disappear (at the times when the temperature meter raised high).

Best regards,

Hans

Hans, well done on your venture, I have a few questions if you dont mind,

Was the original fan electric or belt driven?

Did you replace the thermostat?

Was the cooling system flushed out and new added?

Was the radiator matrix [where the cooling air passes through to cool the coolant} washed out with a pressure washer or blown out with an airline?

That last item is now on a preventative maintainance schedule on big trucks in the UK and is done every 2 months or so.

Rgds, Lickey.

These are good questions.

Unless the vehicle is a thousand years old, there can be no foreseeable reason why your engine should get "hot" if the cooling system is ok (maintained). If it has not been maintained correctly or has another problem (head gasket?), the problem will come back soon enough.

Also, what do you consider "hot"? How did you measure this "hot" temperature?

[Dave the Dude]

Hi hans

Just one thought, does the engine oil look normal when you check the level(dip-stick). If the headgasket is failing you would loose coolant fluid like you say and the engine run hot. The oil usually looks like it has a white film/bubbles in it if water is present.

Good luck and what type of car is it?

Dave

[hans1977]

The oil looks ok, and it only used coolant fluid when i was stuck at a traffic light in the hotter hours of the day.

The car i have is Mazda Familia -92.

Best regards,

Hans

Hi hans

Just one thought, does the engine oil look normal when you check the level(dip-stick). If the headgasket is failing you would loose coolant fluid like you say and the engine run hot. The oil usually looks like it has a white film/bubbles in it if water is present.

Good luck and what type of car is it?

Dave

[Farma]

I made a similar modification on a Nissan. It worked well for near on 10 years and 140,000 km’s. My change was made to provide additional engine power due to living at high altitude rather than a need for increased cooling.

The original viscous coupling fan was removed and an electric fan from a V6 Chrysler fitted. It took some trial and error before I had things working as planned.

I manufactured a separate “T” fitting to install next to the thermostat. On one side I had the temperature gauge sender unit and the other a temperature switch to operate the electric fan. At the time the only temperature switches available to me were from Mercedes. With some trial and error I finally thought I had the correct range temperature switch fitted. It was winter.

The next problem was the aircon stopping whilst waiting at traffic lights in hot weather. The aircon system had a cutout switch that disconnected the compressor if the engine started to come close to overheating. That was solved by wiring the fan so it worked whenever the aircon was turned on and fitting a temperature switch that operated at a lower temperature range.

As they say for every action there’s a reaction, the downsides were a loss of engine braking and a slightly under reading temperature gauge. Removing the viscous coupling fan had taken the load of the engine to such a degree.

Edited May 10, 2008 by Farma

[hans1977]

Interesting. You say it worked well for nearly 10 years and 140000 kms. Does that mean that you found the fan as well as the temperature switch completely reliable as well?

The relay, temperature switch and the fan are my only concerns in this, because they might fail silently and as a result, if i happen to not be watching the temperature gauge at that time, the engine will get overheated.

/Hans

I made a similar modification on a Nissan. It worked well for near on 10 years and 140,000 km's. My change was made to provide additional engine power due to living at high altitude rather than a need for increased cooling.

The original viscous coupling fan was removed and an electric fan from a V6 Chrysler fitted. It took some trial and error before I had things working as planned.

I manufactured a separate "T" fitting to install next to the thermostat. On one side I had the temperature gauge sender unit and the other a temperature switch to operate the electric fan. At the time the only temperature switches available to me were from Mercedes. With some trial and error I finally thought I had the correct range temperature switch fitted. It was winter.

The next problem was the aircon stopping whilst waiting at traffic lights in hot weather. The aircon system had a cutout switch that disconnected the compressor if the engine started to come close to overheating. That was solved by wiring the fan so it worked whenever the aircon was turned on and fitting a temperature switch that operated at a lower temperature range.

As they say for every action there's a reaction, the downsides were a loss of engine braking and a slightly under reading temperature gauge. Removing the viscous coupling fan had taken the load of the engine to such a degree.

[Farma]

Hans

Apart from the initial trial and error phase I had no problems. The relay, temp switch and fan were still original after all that time. The cars still driving around without problem today.

That car operated in temperatures from freezing to 50+ c, at sea level to 10,000 feet, through flood water to deserts without problems. I believe it has over 175,000 kms on the clock now and still going strong.

[hans1977]

Thanks! This is encouraging to read. I do know that all the parts were bought in Thailand, and the temperature switch is for sure not a genuine Honda Civic -92 part, but at least i have bought all the things in a shop where they seam (both from what i have seen as i previously bought other parts there, and from what i have been told by the staff) to care about selling good quality parts. But i can not be sure about the quality anyway, of course...

/Hans

Hans

Apart from the initial trial and error phase I had no problems. The relay, temp switch and fan were still original after all that time. The cars still driving around without problem today.

That car operated in temperatures from freezing to 50+ c, at sea level to 10,000 feet, through flood water to deserts without problems. I believe it has over 175,000 kms on the clock now and still going strong.

[wilko]

I would have wanted to know WHY the overheating was occurring.....because until you know that, you haven't necessarily cured it, rather masked it and it may return.

However those viscous fans are a bit dodgy with age, so that might have been the cause anyway.

A general observation though....leaving your vehicle idling in hot weather with the air-con on is not a good idea....thw engine is under more stress than tick-over and th cooling airflow is restricted to only that which the fan can provide...this in turn is powered by the battery/alternator and ultimately the engine!

[cali4995]

Hans1977, you certainly seem to have just engineered your own solution to the problem. The weather in

Thailand is probably on the extreme side of where these vehicles were designed to operate. Radiator

caps are rated in psi. Cooling systems are pressurized as this raises the boiling point. On the neck of the

radiator will be a blow-off tube which leads to a smaller plastic receptical tank. Maybe this is where some

of your coolant is going? Also, an anti-freeze/water mix has a higher boiling point than water alone. Taking

out the thermostat might be fine here, but in cooler climates, the engine would never properly warm-up.

[wilko]

Why would you put anti-freeze in an cooling system in Thailand?

One thing that has impressed me in Thailand is the ability of the cars I've experienced to cope quite easily with the hot weather...even being left on tick-over with the air on.......I would assume that the spec is adjusted for the climate....

[stingray]

You add antifreeze or coolant to the engine water, to protect the engine from corosion, not only for incrising the boiling point.

Your relais, swithc or teperature sensor could fail and the engine could be damaged if you don't watch the temperaturegauge.

There is another easy installation option:

Fit a control light or a light diode, for controlling the engine fan in your console or dashboard. One wire you conect with the ignition switch at No. 15 (exit) The second wire you connect at the PLUS SIDE cable (input) just before it go in to the engine fan. So the trick is: If your engine get started the control light (if everything works properly), get 12 V plus from BOTH sides and will not show at all. If you fan get no electrical power incase of a faulty relais switch or anything else like a faulty electrical connection, your control light get 12+ from one side and ged ground (- minus) from the electric fan side and will start glimming. Sou you'll see immidently that the engine fan not work.

[wilko]

Then I would put an anti corrosion agent but not one particularly selected for it's anti-freeze properties.

[hans1977]

Yes, it's a bit hard on the battery/alternator, but that's why i have the _option_ to switch the fan on when the air condition is on. That way i will be able to let the battery/alternator rest from the late afternoon to the late morning the day after.

Other than that i just think my car is to old for the modern thai-traffic-jam-culture...

/Hans

I would have wanted to know WHY the overheating was occurring.....because until you know that, you haven't necessarily cured it, rather masked it and it may return.

However those viscous fans are a bit dodgy with age, so that might have been the cause anyway.

A general observation though....leaving your vehicle idling in hot weather with the air-con on is not a good idea....thw engine is under more stress than tick-over and th cooling airflow is restricted to only that which the fan can provide...this in turn is powered by the battery/alternator and ultimately the engine!

[hans1977]

Yes, engineering is fantastic!

I think a thermostat has never been in my car. At least it hasn't since i bought it...

/Hans

Hans1977, you certainly seem to have just engineered your own solution to the problem. The weather in

Thailand is probably on the extreme side of where these vehicles were designed to operate. Radiator

caps are rated in psi. Cooling systems are pressurized as this raises the boiling point. On the neck of the

radiator will be a blow-off tube which leads to a smaller plastic receptical tank. Maybe this is where some

of your coolant is going? Also, an anti-freeze/water mix has a higher boiling point than water alone. Taking

out the thermostat might be fine here, but in cooler climates, the engine would never properly warm-up.

[wilko]

I guess age will take it's toll.

i was musing about a thermostat and of course in a cold climate it allows the engine to quickly reach operating temp but it also keeps water in the radiator so it can be cooled by the airflow.

I guess the cooling system on a car in Thailand would have a larger amount of fluid and a bigger radiator than say Northern Europe?

...and of course at a standstill it is practically only cooled by the airflow generated by the fan....which in turn would shut off a speed?

Edited May 19, 2008 by wilko

[hans1977]

But that option would only be good if the electrical cooling fan was _not_ controlled by a thermo switch _and_ provided that the fault of the fan is _not_ the windings or brushes of the fan motor, right?

/Hans

You add antifreeze or coolant to the engine water, to protect the engine from corosion, not only for incrising the boiling point.

Your relais, swithc or teperature sensor could fail and the engine could be damaged if you don't watch the temperaturegauge.

There is another easy installation option:

Fit a control light or a light diode, for controlling the engine fan in your console or dashboard. One wire you conect with the ignition switch at No. 15 (exit) The second wire you connect at the PLUS SIDE cable (input) just before it go in to the engine fan. So the trick is: If your engine get started the control light (if everything works properly), get 12 V plus from BOTH sides and will not show at all. If you fan get no electrical power incase of a faulty relais switch or anything else like a faulty electrical connection, your control light get 12+ from one side and ged ground (- minus) from the electric fan side and will start glimming. Sou you'll see immidently that the engine fan not work.

[hans1977]

I suppose this wouldn't be complete until i've tried the fan in Bangkok as well...

I went there a couple of days ago, and i spent quite a lot of time on waiting for the cars in front of me as usual. The engine kept away from boiling all day long, and the AC was working well enough to keep me "cold".

/Hans

Hi,

I've just fitted an electrical cooling fan behind the radiator of my old secondhand car to try to solve the problems i used to have:

1) The engine got very hot (sometimes even started boiling a little) at the traffic lights in a hot day (thus, nearly every day), and to go to Bangkok wasn't really worth even thinking of.

2) The old fan was not in a good condition.

3) The AC wouldn't produce enough cold air at low speed in the day time.

So, i grabbed my pen to plan for a new electrical system. It has got the usual things (such as temperature switch, the actual fan and a relay), as well as an additional relay, an emergency switch and an option selector switch (to select if the fan should run when the AC is on, or not).

The fan is very efficient, and problem number 1 and 2 seams to belong to the past now. I have also tested the usefulness of the option switch and discovered that problem number 3 more or less disappears as i pull the switch.

As a bonus i've also noticed a slight decrease in fuel consumption.

I have found the hard parts of this project to be to find a suitable fan and to find out where and how to fit the temperature switch.

To find a suitable fan i actually had to bring my tools to the shop and disassemble the old system followed by trying to place the fans, one by one, from the shop until i had one that appeared to be the most suitable.

I'm really happy with the system that i've got, and i would recommend anyone with similar problems, to what i had, to have an electrical cooling fan installed.

I would also recommend to plan the job well and buy all the parts before you start if you decide to do it your self. The first part to buy would be the fan, i'd suggest.

You could also do the work in steps, like i did, and fit everything but connect an indicator light instead of the fan to see if everything is working before you've already removed your old system.

Best regards,

Hans

[stingray]

But that option would only be good if the electrical cooling fan was _not_ controlled by a thermo switch _and_ provided that the fault of the fan is _not_ the windings or brushes of the fan motor, right?

/Hans

You add antifreeze or coolant to the engine water, to protect the engine from corosion, not only for incrising the boiling point.

Yes Hans, you are absolutely right. But 90% of the failures come from connections, plugs and faulty relais or even burnet or melted fuses or fuseboxes. You can refine this options as you can connect the lightbolb insteat to 15 (ignition) to the ignitionswitch ACC position(accessories). So anytime when you open the ignition switch to ACC, you lightbolb will glimm and when you tur your key to ignition, fan will get power and lightbolb will stop glimming. With this option you can control anytime that the brushes and the wiring of the fan still in working condition. But to connect the fan i would not use any termostate and termo switch, just connect the fan over a relais to the ignition switch. In Thailand is so hot, that is no problem if the fan works allways. That's mean you connect the relais as follow:

No. 30 over a fuse box to the battery +.

No. 85 to the exit of the ignition switch 15 or Accessiories.

No. 86 to the starter switch. (you can see one big cable (input) comming from battery plus and is connected to the magnitic switch of the starter motor and anotherone (very short) cable come out from the magnetic switch and go the the brushes (output). On "Output" you connect a wiring to 86 on the relais. This will stop the fan for a couple of seconds when your starter cranking. So you get more power to the startermotor.

No. 87 goes to the electric fan input

No car is to old for Thailand Traffic conditions. Make sure the electric fan or maybe two of them, works properly. This is the cheapest option. If you get a better result but engine still overheating and your Headgasket is ok, than you have to sonsider for a larger engine radiator.

[hans1977]

Thanks for your suggestions! I will keep the idea in mind and try to do something useful about it and still keep the thermo switch.

I think the thermo switch is very nice to use before about 10 am. and after about 4 pm. since i've discovered that the fan is usually switched off at that time. In the night the fan actually hardly switches on at all!

My alternator is quite small, so i think it does it only good if i there are times when the fan is not switched on.

Maybe there are cars with mechanical fans that are perfectly ok here, but mine wouldn't manage, especially not in Bangkok, without it.

/Hans

But that option would only be good if the electrical cooling fan was _not_ controlled by a thermo switch _and_ provided that the fault of the fan is _not_ the windings or brushes of the fan motor, right?

/Hans

Yes Hans, you are absolutely right. But 90% of the failures come from connections, plugs and faulty relais or even burnet or melted fuses or fuseboxes. You can refine this options as you can connect the lightbolb insteat to 15 (ignition) to the ignitionswitch ACC position(accessories). So anytime when you open the ignition switch to ACC, you lightbolb will glimm and when you tur your key to ignition, fan will get power and lightbolb will stop glimming. With this option you can control anytime that the brushes and the wiring of the fan still in working condition. But to connect the fan i would not use any termostate and termo switch, just connect the fan over a relais to the ignition switch. In Thailand is so hot, that is no problem if the fan works allways. That's mean you connect the relais as follow:

No. 30 over a fuse box to the battery +.

No. 85 to the exit of the ignition switch 15 or Accessiories.

No. 86 to the starter switch. (you can see one big cable (input) comming from battery plus and is connected to the magnitic switch of the starter motor and anotherone (very short) cable come out from the magnetic switch and go the the brushes (output). On "Output" you connect a wiring to 86 on the relais. This will stop the fan for a couple of seconds when your starter cranking. So you get more power to the startermotor.

No. 87 goes to the electric fan input

No car is to old for Thailand Traffic conditions. Make sure the electric fan or maybe two of them, works properly. This is the cheapest option. If you get a better result but engine still overheating and your Headgasket is ok, than you have to sonsider for a larger engine radiator.