johns90

Active Member
The interior fan on my D reg 90 only works on the highest setting. Before I go stripping does anyone have any ideas??????
 
i think the variable speed widget is in the air intake side under the bonnet between the wing and the heater box.
Mine was playing up and was because i had knocked the earth wire off the switch in the binnacle.


Lynall
 
My heater only works on full too. To be honest though ive never tried to fix it because in the winter I only ever want it blowing on full.
 
The main problem is yes the `heater` fan works only on full but I never said the heater works. The heater system in the winter is hat, scarf, and wooly gloves. Its usefull at the moment as a demister for those wet days
 
The ballast resistor will be knackered, not an uncommon problem and replacement is possible.


Your heater should give out plenty of heat if the cooling system is working correctly, heater controls are set up right and the heater is in good nick.
The heater gets its heat from the circuit before the coolant goes through the rad so it should warm up as soon as the block is warm, coolant only flows through the rad when the engine is at operating temperature and the thermostat opens up (at 84 degrees?) to cool the coolant. The coolant flowing through the heater will be at engine operating temperature and if this is too low then it indicates a sticky thermostat (constantly allowing the coolant to flow through the radiator). Blocking off the rad on an otherwise correctly working system just means that when the coolant DOES require cooling there will be no air-flow to do this.
If the edges of the matrix aren't sealed against the heater-box then air can bypass the matrix likewise if the heater-box seals aren't very good cold air can get drawn-in that way as well.
Adjustment of the heater flaps is the easiest thing to check and have the biggest effect. If the flaps are incorrectly adjusted or not sealing then you don't have any chance of getting any decent heat through but 10-minutes spent adjusting the cables will make it all warm & toasty in the winter.
 
Hi all I have a similar problem, the fan works well and so does the direction of the flow of air, but I get cool/luke warm air that's it?!! what are the ways of fixing this?? Is there a sticky anywhere about how to adjust the flaps as mentioned above??
Cheers
Oli
 
Hi all I have a similar problem, the fan works well and so does the direction of the flow of air, but I get cool/luke warm air that's it?!! what are the ways of fixing this?? Is there a sticky anywhere about how to adjust the flaps as mentioned above??
Cheers
Oli

From what i have read about defender motors they tend run on the cool side. What we do here in the USA is we put in different temp. thermostats for the different climates. ie 160 170 180 degree F. Could you change to a lower temp. thermostat? Or put on a grill blanket to reduce air flow over the radiator?
 
The interior fan on my D reg 90 only works on the highest setting. Before I go stripping does anyone have any ideas??????

Hi
I had this with my 110. I check the contacts of the switch mechanism and found the switch it self to be the cause. I tried cleaning contacts and bending bits to help, but it didn't cure the problem
For a while I ran with a toggle switch hanging out the dash until i go a 2nd hand replacment.
All is now ok.
 
"From what i have read about defender motors they tend run on the cool side. What we do here in the USA is we put in different temp. thermostats for the different climates. ie 160 170 180 degree F. Could you change to a lower temp. thermostat? Or put on a grill blanket to reduce air flow over the radiator?"

My 300TDi has the standard thermostat in it (84 degrees C?) and that opens & closes just fine even in the depths of the UK winter we had last year. If you wanted it warmer I think you can get a 92 degree C(??) but I would check your existing thermostat is working ok first.
Don't forget that as long as the thermostat is working correctly there won't even be any hot coolant flowing through the radiator until that temperature has been reached however the coolant in the jacket is the same as that flowing through the matrix so if the matrix is cool then it means your cooling system needs looking at (a partially open thermostat not only means a less effective heater but also means your engine is running too cool and that isn't a good thing).

With regards to adjustment of the cables it is dead easy and as soon as you take a good look at how the heater works it all becomes clear.
The LH lever not only operates the 2-speed fan but in the upper position closes the flap between the heater and the bulkhead blocking any flow of air.
The RH Temp lever adjusts the flap inside the heater. On the hot setting it diverts all the air through matrix, on the cold setting it diverts it via the bypass channel thus avoiding the matrix altogether and any position inbetween mixes the hot & cold air to provide varying levels of warm.
The Up/Down lever operates the flaps in the lower section of the dashboard and diverts air either through the lower or windscreen vents.

A common problem is that the outer sheath of the cable moves in its clamp so while you think you are moving the flap you are in actual fact doing nothing. Remove the levers and ensure that the sheath is correctly secured and the cable lubricated, next operate the levers and check that the flap is moving as it should (if you move it smartly you can hear a thump as it closes). It really can take only 10-minutes to adjust them correctly.

My 300TDi soft-top runs a viscous fan and does NOT have a rad-cover yet the air coming out of the heater-vents last winter was in excess of 60 degrees C and made my cab nice and cosy. I don't have any carpets or sound deadening but I do have a fume curtain.
 
Just be careful if you adjust the cables. The clip that holds the hot/cold lever onto the shaft at the top of the box has broken on mine and they are not available. Official dealer says you have to buy a new box!!
There must be a bucket of them somewhere in the factory but there's no part number for it (or the arm) so can't be found/sold. :confused:

And they wonder why there are bodges around.

Malcolm
 
I think the heater prob is the thermostat, which I have in the garage but no time at the mo. Its the fan only working on full speed that is the issue.
Will sort all this out in the next few weeks.
 
Hi
Been reading through threads on heater motor switch, need to replace but as i only ever have in full on want to just use a toggle switch, could you let me know how you wired it up and type of switch ?, how did you handle the earth which is on the switch plate?
Much appriecated
Cheers
 

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