Fan Speed Control Assembly

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JockHiltz

JockHiltz

Member
Posts
52
Location
Halifax, NS, Canada
Question about the Fan Speed Control Assembly... I've lost all control of my fan speed, does the dash Fan Speed Control Assembly have a resistor bank in it that could go that could cause me to loose fan control? My old jeep wranglers had a small resistor bank on in the dash that set the fan speed... wondering if the Defenders have a similar thing... looked at the diagrams on LR workshop, but didn't see anything similar.
 
JockHiltz said:
Question about the Fan Speed Control Assembly... I've lost all control of my fan speed, does the dash Fan Speed Control Assembly have a resistor bank in it that could go that could cause me to loose fan control? My old jeep wranglers had a small resistor bank on in the dash that set the fan speed... wondering if the Defenders have a similar thing... looked at the diagrams on LR workshop, but didn't see anything similar.
Click to expand...
Most of the time when the resistor is to blame the fan only runs at high speed and won't switch to lower speeds. Is that the case with yours?
 
JockHiltz said:
hahaha I'm Canadian, so don't stress to much about English terminology.
Click to expand...

Me too, although as I have lived in Britain a long time I have had to learn to speak proper! :)

I was in Halifax in October, interesting place. Or what I could see of it was, it was pretty foggy most of the time.

What sort of vehicle do you have?

Assuming a Defender, as you have posted in the Defender section?
 
Turboman said:
Assuming a Defender, as you have posted in the Defender section?
Click to expand...

It is ... by a bit of sleuthing I have determined that Mr @JockHiltz has a 2003 D90 with a TD5 engine (that starts hard .....).

So, no there are no resistors in the dash. They are in the intake of the motor/fan assembly.
12V is presented to the control lever in the binnacle and is passed in pos 1 through the resistor (low speed) or directly to the motor (pos 2)
There is a plug which lies just behind the fan where you can check to see if 12V is present.
If not which the steering wheel off and open up the binnacle and see if voltage is there ...
If not it's check the fuses time.

If you look at the picture, where the wires go in through a 'hatch' the resistor is below that ...

.
Def-heat.jpg
 
Turboman said:
Me too, although as I have lived in Britain a long time I have had to learn to speak proper! :)

I was in Halifax in October, interesting place. Or what I could see of it was, it was pretty foggy most of the time.

What sort of vehicle do you have?

Assuming a Defender, as you have posted in the Defender section?
Click to expand...
hahah yes, Halifax is either sunny or foggy... no in between, hahaha

I have a 2003 Defender 90 TD5, should have added that at the top post, haha
 
miktdish said:
It is ... by a bit of sleuthing I have determined that Mr @JockHiltz has a 2003 D90 with a TD5 engine (that starts hard .....).

So, no there are no resistors in the dash. They are in the intake of the motor/fan assembly.
12V is presented to the control lever in the binnacle and is passed in pos 1 through the resistor (low speed) or directly to the motor (pos 2)
There is a plug which lies just behind the fan where you can check to see if 12V is present.
If not which the steering wheel off and open up the binnacle and see if voltage is there ...
If not it's check the fuses time.

If you look at the picture, where the wires go in through a 'hatch' the resistor is below that ...

.View attachment 283442
Click to expand...
good sleuthing.. haha

So am I reading it right, there is no resister bank? so would you have to replace the whole fan assembly? is it on the driver side?
 
JockHiltz said:
good sleuthing.. haha
So am I reading it right, there is no resister bank? so would you have to replace the whole fan assembly? is it on the driver side?
Click to expand...

Look here at this eBay offering. https://www.ebay.co.uk/itm/175137423476
This is the empty box
There is a rectangular hole on the fan body .... this is where the reistor goes to slow the fan down.
There is only 1 resistor.
It dangles in the air stream so it can be cooled.
You can replace it easily.

Check your voltages first, power goes in, through the resistor and back out to the motor (slow) or directly to the motor (fast).
You can buy spare motors if yours has failed (although this is not likely it can happen).

Stand back, on a box, lift the boonnet and send us a picture of the engine bay
 
JockHiltz said:
oh great! so just snip out the old one and solder this in the old harness?
Click to expand...

Yes.

The fan motor is 12V. Fast speed current is around 7A slow speed is 2A, resistance of the original resistor is around 4 Ohm.(4R5)
Putting in a 4 or 5 Ohm will drop the speed to similar to the original.
If you want the fan to run a bit faster on the slow speed (as I did) you substitute a smaller resistor, a value such as 3 Ohm would increase the current to 2.5A, the resistor would then be dissipating 20W hence you need a (twice that value) resistor to dissapate the heat and not burn up.

Like this (faster) one .... https://uk.farnell.com/arcol/hs50-2r-f/resistor-wirewound-2r-1-axial/dp/2678691?st=2Ohm
Or this (slightly faster) one ... https://uk.farnell.com/arcol/hs50-3r-f/resistor-wirewound-3r-1-axial/dp/2678696?st=3Ohm
Or this (same speed) one ... https://uk.farnell.com/arcol/hs50-4r-f/resistor-wirewound-4r-1-axial/dp/2678699?st=4Ohm

To keep it extra cool you dangle it in the airflow (like the original), or you could mount it externally bolted to the bulkhead or the heater box itself, for example, which would act as a heatsink.
 
miktdish said:
Yes.

The fan motor is 12V. Fast speed current is around 7A slow speed is 2A, resistance of the original resistor is around 4 Ohm.(4R5)
Putting in a 4 or 5 Ohm will drop the speed to similar to the original.
If you want the fan to run a bit faster on the slow speed (as I did) you substitute a smaller resistor, a value such as 3 Ohm would increase the current to 2.5A, the resistor would then be dissipating 20W hence you need a (twice that value) resistor to dissapate the heat and not burn up.

Like this (faster) one .... https://uk.farnell.com/arcol/hs50-2r-f/resistor-wirewound-2r-1-axial/dp/2678691?st=2Ohm
Or this (slightly faster) one ... https://uk.farnell.com/arcol/hs50-3r-f/resistor-wirewound-3r-1-axial/dp/2678696?st=3Ohm
Or this (same speed) one ... https://uk.farnell.com/arcol/hs50-4r-f/resistor-wirewound-4r-1-axial/dp/2678699?st=4Ohm

To keep it extra cool you dangle it in the airflow (like the original), or you could mount it externally bolted to the bulkhead or the heater box itself, for example, which would act as a heatsink.
Click to expand...

Great, thanks so much! and where exactly is the current resisters located? best way to access it?

I'm gonna check the fuses first, but as I previously mentioned, the past two years the fan has only worked on high speed.

thanks again
 
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