A bit of an unexpected story here. Our Disco has Flex-a-lite twin electric fans instead of the horrible factory serpentine belt driven OE unit. Great improvement in noise and a little better fuel econony. A few days ago the electric fans quit due to a broken off power wire. Engine started to overheat. Jerry-rigged a new power line from the battery and got home OK. Yesterday it dawned on me that the AC system has its own electric fans in front of the rad. Tried driving with only the AC fans pushing air - 25 Celcius degrees outside (about 77 Fahrenheit). As I suspected, the engine stayed cool using only the AC fans and with no 'puller' engine fans at all. I'm sure this is not news to other Rover owners but it was a pleasing realization that she's got a partial backup cooling system in the AC fans. Wow, live and learn! Now all I have to do is get the regular fans going again.
I have been having overheating issues offroad - and on road at low speed. I am in dire need of a cooling system flush, and a new temp sender (guage reads low - even when boiling)
The AC running causes to heat up even more... now heres a little hint
Unplug the AC compressor, but turn on the AC and keep the interior fan running at "1" or above... your AC pusher fans will run WITHOUT adding heat to the incoming air from the AC condensor
I am going to be putting two electric fans on her - and removing the faulty viscous clutch. This will be about the same cost as replacing the clutch!
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Black '02 Discover SII, Auto.
Black '87 Suzuki Samurai, rock crawler :
Black '94 Discovery SI V8i, 5 spd (Currently DOA)
--## If you have enough time to do something over again, you had enough time to do it right the first time. ##--
Unplug the AC compressor, but turn on the AC and keep the interior fan running at "1" or above... your AC pusher fans will run WITHOUT adding heat to the incoming air from the AC condensor
Excellent tip--that's one I'm keeping in my toolbag!
Black Magic - yes I'll post a few pix of our Flex a lite system soon. We have the twin fan #210 unit made in Washington State ($369 Canadian, bought mid 2002). The fit is remarkable in that it looks like it was designed for the Disco Rad. All I did was make two little metal clips for the upper edge of the new fan shroud and use sheet metal screws in existing radiator surround holes to hold everything in place.
I just updated the control panel to the new 'Variable Speed Control' unit ($109 Canadian). The orginal control unit that came with the fans 'lost' the male 12 volt power plug recently (it desoldered itself due to an electric motor brown-out! The tech guy at Flex a lite said the brushes on the fan motors get a glaze on them when not used enough and this causes a large power demand when the fans are turned on. Fixing the old panel was not practical and besides, the sensor was the old type capillary that fits into the upper radiator input port. This copper capillary is a bit tricky to install so that you don't bugger it up or have a slow coolant leak from the top rad hose. The new 'Variable Speed Control' panel uses a SS probe that you push into the rad between the cooling vanes. We'll see how it all performs over the remainder of the summer.
You might want to install a real temp guage and a bypass switch/timer for the A/C fans just in case reality got real busy. Have it shut down after 10 minutes off ignition. Should save your battery unless you got dualies.
Black Magic. Here's two pictures that might help you. http://www.members.shaw.ca/tetracant...Rover/Fans.jpg http://www.members.shaw.ca/tetracant...Controller.jpg
The flex a lite dual fan shroud has a rubber gasket around its flange - sort of like the welting around your doors. This gasket is crushable and makes a nice seal to the rad core fins. The bottom of the shroud pushes into the rad metal surround and needs no attachment. I only used two clips in the top of the shroud - very easy. The electrical hookup may need a creative touch however!
There is a way to wore up the AC fans to where you can run them separately from the actual AC....But, I don't know how. Yet, I've seen it done. It was just a jumper wire and switch. The jumper wire is mounted to some ECU behind the glove box (on a 97 D-90) I'll see what I can find out....
It should be possible to do it easily using the controls from flex-a-lite and similar manufacturers - The unit I got for the twin electric fan conversion is made by Hayden automotive and has an AC clutch input, and a thermostat that is inserted in the radiator. I think the cost was around US$60.
The trick would be to supply this relay with fused 12V, and use it to drive the AC fans. All of the wiring for this would be done in the engine bay and in front of the radiator.
The AC input would make the fans operate the same as before the conversion, and the thermostat would act as an extra control, turning them on when the temperature climbed.
Not sure the AC fans could replace the flow from the water pump fan though. It'd certainly be better than nothing and provide a little more insurance for cooling in the event of a main fan failure.
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Black '02 Discover SII, Auto.
Black '87 Suzuki Samurai, rock crawler :
Black '94 Discovery SI V8i, 5 spd (Currently DOA)
--## If you have enough time to do something over again, you had enough time to do it right the first time. ##--
pavel i for 1 would stick with the original serpintine driven fan if you do any serious off roading and or river crossings. I have seen 2 many cooked engines through blokes trying to save a couple of pennys on fuel economy.
Good point Brighty, I agree with you completely. I can switch back to the OE fan and remove the Flex a lite fans in about 15 minutes. In my case, we only go off-road in large groups a few times a year - 90% of the time our Disco is a boulevard hopper. Also, being an 'oldtimer', I tend to watch the temp (and any other) gauges every few minutes, just expecting something to go wrong with any Brit car. My training by 'Lucas - the Lord of Darkness' in the 60s and 70s has served me well over the years. Sorry, hope I haven't offended any ex-Brits or monarchists....
Location: Bloomfield, CT If I died today, I lived there all my life.
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I would have to disagree with brighty about the fans. Kenlowes, and Fex-O-Lite are a well sealed motor unit and should'nt be affected by water. If you got in deep enough to submerge the motors, you have bigger problems than getting them wet. Engine driven fans with thermostaticly operated viscous clutches are efficient, but somewhat slower to react to rapid temperature increases. When they are locked up, they are using a lot (about 12 HP) of power.
When making water crossings, where the water level is such that the fan will throw water, and electric fan can be shut off with a wired in switch, but not so with an engine driven fan. Some people say" Just take the fan belft off. Not with my handbuilt engine, thanks, I like the waterpump circulating coolant.
Much of the dry off roading we do is at speeds so slow that air movement by forward motion is minimal, and engine driven fans need to be goosed periodically to get some airflow. Electrics will force plenty of air through. The newer fans use a solid state device to vary the fanmotor speeds rather than just on/off. Almost all of the electic fans offered today use brushless motors.
Two weeks ago I was stuck in traffic for at least 2 hours. It was around 90 out and I had the A/C on. Although I did not overheat, the engine compartment got so hot the power streeing fluid started boiling over and my snorkel hose collapsed. Thankfully the hose was not connected at the time. I am now convinced electric fans are the way to go. I plan on using an adjustable thermostatic switch and a manual shut off for water crossings.
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Jeff
1992 Range Rover
1994 Discovery 5 speed
I would have to disagree with brighty about the fans. Kenlowes, and Fex-O-Lite are a well sealed motor unit and should'nt be affected by water. If you got in deep enough to submerge the motors, you have bigger problems than getting them wet. Engine driven fans with thermostaticly operated viscous clutches are efficient, but somewhat slower to react to rapid temperature increases. When they are locked up, they are using a lot (about 12 HP) of power.
When making water crossings, where the water level is such that the fan will throw water, and electric fan can be shut off with a wired in switch, but not so with an engine driven fan. Some people say" Just take the fan belft off. Not with my handbuilt engine, thanks, I like the waterpump circulating coolant.
Much of the dry off roading we do is at speeds so slow that air movement by forward motion is minimal, and engine driven fans need to be goosed periodically to get some airflow. Electrics will force plenty of air through. The newer fans use a solid state device to vary the fanmotor speeds rather than just on/off. Almost all of the electic fans offered today use brushless motors.
sorry terrys but i still disagree as thermatics are not spinning all the time.If you get into some seriouse mud it can get lodged between the thermatics and the radiator rendering them useless.
where i live we have a lot of clay mud and my experience is that thermatics are only a good thing if you dont off road.
Engine fan not needed?
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Just a idea:
Linear Mode
