Radiator fan conversion.

**DoubleChevron** · 27th December 2015, 04:28 PM

Hi Guys,

The rangie is still in bits in the shed ... waiting on CV's and the alloy bracket to hold the LT230 shifter mechanism in .... So I thought I'd tackle the radiator fan while it's not drivable.

Well the clutch fan in the old Rangie works perfectly .... it appears except for on hot days when your stuck in traffic down in melbourne due to a car crash. I watched the (aftermarket) gauge slowly creep up to 95degrees ..... even rolling along at less than walking pace for 30seconds would drop the temp back to 90degrees. Throwing it into nuetral and revving the motor probably would have bought that stupid fan clutch in. Certainly as soon as you started driving the radiator fan would be roaring away like buggery. Even at 95degrees... that god damn piece of **** dash gauge was dead center. I'd rather have no gauge, than one that lies to you and doesn't move at all .... 40degrees and 95 show exactly the same position... middle gauge. I wonder when it moves to the "hot" portion of the gauge? I'm guessing after you have cooked the motor.

Anyway, I priced a new fan clutch and near bloody fell over ....

yes, this is probably the millionth thread on electric fans conversion. As suggested all over the threads on this forum I've grabbed an EL falcon fans. I just looked at the local facebook groups and right there on top was someone wrecking falcon 5minutes drive from my place.... So $25 bucks later I have a set of fans that work. The actual fitting of the fans has been covered 100times on here, so I'll leave that alone.

However .............................. Wiring. I was about to sit down and draw up a circuit diagram and thought ............... Bugger this, why re-invent the wheel ?? So I google series/parallel fan circuits and stumbled across this one.

Bloody ripper right? I can't see a problem. All I need it 3 relays. I was looking at the rangie thinking, how the bloody hell do I drive the relays............ Scratched my head.... Looked at the stupid lying dash gauge temp sender .................. Hmmmmm..... Now a lot of european cars have twin thermistor temperature senders.... I have a couple of spare for my Citroen CX. So I unscrewed the dash gauge sender .... I'll be bloody damned if the Citroen CX low/high fan thermo switch didn't screw in. It's the identical thread too. The above diagram will match perfectly. At 86degrees the low speed fan will run ( series circuit ) and 92degrees the high speed fan will kick in ( parallel).

Can anyone see any probems? I'll stick it an 4th relay and drive the low speed fans from the condenser fans too. So if the condenser fans (ie: air con ) is running, we'll also turn on low speed radiator fans to help air flow through the condenser.

seeya,
Shane L.

**gavinwibrow** · 27th December 2015, 04:59 PM

So, all you need then for total satisfaction is a gauge to show the real temp, and possibly a fan over-ride switch in case everything else fails, then you can drive to the moon and back!

**DoubleChevron** · 27th December 2015, 05:44 PM

Originally Posted by gavinwibrow

So, all you need then for total satisfaction is a gauge to show the real temp, and possibly a fan over-ride switch in case everything else fails, then you can drive to the moon and back!

If your concerned about switches, just earth low and high fan back to a switch in the cabin. Overkill IMO. This is the same setup used on my other cars for decades. Failure mode is almost always no low speed fan and only one fan on high speed (which means you have a dead fan or wiring/connector issue in the series/parallel relays).

I like it due to the simplicity and lack of user intervention required

seeya,
Shane L.

**DoubleChevron** · 28th December 2015, 03:52 PM

I thought this was the temp gauge sender in the thermostat housing .... As soon as I had it out it was obviously a switch.

I hit it with the hot air gun to test it ..... yep, it got that hot it melted but never switch on

Oh well, it was already dead to begin with.

I screwed on of these in ... exactly the same thread. It's a switch from a 1985 Citroen CX2500 GTi Turbo. They are a twin thermister switch. 86 degrees and 92 degrees. So at 86 degrees the fans will turn on in series (low speed) and at 92 parallel (high speed).

First ... I checked the wiring to the existing sensor for continuity to earth. And there was none.

So I bridged it ..... Get this, the bloody clowns at rover have run the full condenser fan current through the switch. No wonder it was dead and didn't work. You should just use the switch to drive the earth pin of a relay! I'll just leave this disconnected. With proper radiator fans, the wheezy condenser fans aren't required for engine cooling, we'll just leave them wire only to the A/C. Oh yeah .... If you have a classic, your condenser fans will not work when the engine is hot ..... You need to replace the thermo-switch on the thermostat housing and wire them through a relay .... Otherwise you'll have no fans when stuck in traffic!

How simple is this .... all up this has cost $25 bucks for the fans and that's it.

**DoubleChevron** · 28th December 2015, 03:53 PM

I just twisted all the wires together to test it .... It works brilliantly. The EL falcon fans move HEAPS of air, they sure are nice to stand infront of in a hot shed

seeya,
Shane L.

**Mister_white_keys** · 28th December 2015, 04:28 PM

Looking good Shane,

I'm running the EL twin fans on my 2 door and they work a treat. I've gone the simpler option of a single temperature switch (on at 92, off at 86 for memory but could be wrong).

I wired them up with a relay for each fan to give them the most beef and then just a 2 position switch for "Auto" and "Override". If it's a hot day and she's pulling a load up a hill I just switch the fans on to give it some constant airflow rather than cutting in and out.

They definitely work much better than the original engine fan and cut out a whole heap of noise during normal operation as well.

Cheers,
Steve

**DoubleChevron** · 28th December 2015, 07:29 PM

Your not wrong... It sounds amazing without the bloody great fan screaming away. I have just however found a problem with the aftermarket temperature controller I fitted. I still need to mount the fans and tidy the wiring .... But figured I should test it.

I fired it up ... sounds amazing... anyway, I left it idle until the fans cycled on low speed ... And they switched on at 75degrees

WTF ? the temperature switch I fitted must be no good. So I hooked up the thermometer probe to my mutlimeter. And watched what was going on. The fans cycled on low speed at 85degrees and off about 40seconds later at 82 degrees.

If you have fitted one of these:

http://www.aulro.com/afvb/showthread...70#post2471270

THEY LIE !!!! This car actually got quite hot sitting in melbourne traffic... Probably 105degrees given the dash gauge said 94. The bloody factory temperature gauge was STILL DEAD CENTER .... NORMAL RUNNING TEMPERATURE. .... Damn, I think I'm going to have to fit a quality aftermarket unit to this car just so I know what the hell is going on!

seeya,
Shane L.

**gavinwibrow** · 28th December 2015, 07:46 PM

Originally Posted by gavinwibrow

So, all you need then for total satisfaction is a gauge to show the real temp,

Sorry Shane - could not help myself!

**mick88** · 28th December 2015, 08:06 PM

Have you considered also wiring an over-ride switch via the brake light switch so that when you have your foot on the brake, the thermo fans also cut in.
Given that your vehicle warms up when you are stuck in traffic, you might find this to be beneficial.

Cheers, Mick.

**DoubleChevron** · 28th December 2015, 08:14 PM

Originally Posted by mick88

Have you considered also wiring an over-ride switch via the brake light switch so that when you have your foot on the brake, the thermo fans also cut in.
Given that your vehicle warms up when you are stuck in traffic, you might find this to be beneficial.

Cheers, Mick.

That's funny, and quite sensible

Nah, she'll be right. Series/parallel has been working reliably in some of my cars for 40years .... So long as the temperature sender doesn't die (it's only switching relay currents) you should never have an issue!

seeya,
Shane L.

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