Heater Fan, doesn't work until it's spun

Sorry if this has been done to death already, but I can't find anything similar by looking.

Hi there all,
I've got a heater fan which doesn't switch on with the switch, I have to get out, pop my hand in the bonnet and spin the fan with my fingers, once it's going, it keeps going, but it needs the initial manual input.

When I spin it, it's not that resistant to being spun, and it's had some contact cleaner with grease sprayed on it (at the garage), but that's not really helped.

Any suggestions? Is it a low voltage thing, a high resistance thing, something to do with the resistor, just needs taking out and cleaning up??? Any suggestions would be awesome.

Also - I did notice that there isn't any sort of air filter on the intake or anywhere else as far as I can tell, has anyone thought of popping anything on there, and if so, what did you use?

Thanks
(ex-Mil One Ten, but now has a 200TDi engine)

I'm not sure what fan you have, but if it's the defender snail type they are not expensive or hard to change.

Either worn brushes or broken wire giving limited voltage

gazman said:

I'm not sure what fan you have, but if it's the defender snail type they are not expensive or hard to change.

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Yeah - it's the black snail!

freelance said:

Either worn brushes or broken wire giving limited voltage

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OK - Should I give it a direct feed to see if it spins up, and if it does, replace the wiring, and if it doesn't its the bushes?
If it's the bushes, I assume it's a replacement unit?

Bearings, dead common, they have them little circular oiltite jobs and as they age they dry out, seize on the shaft, then the bush/bearing spins in the housing instead.
I replaced my fan assy a year or two back 75 quid Iirc.

lynall said:

Bearings, dead common, they have them little circular oiltite jobs and as they age they dry out, seize on the shaft, then the bush/bearing spins in the housing instead.
I replaced my fan assy a year or two back 75 quid Iirc.

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OK - so WD40, wire direct to the terminal to see if that works, then replace the blower motor if all of that fails.
Thanks!

No, dont use wd40, dont be wiring things direct to anything, first check the voltages at the connections to the motor, that will tell you what you need to know. It could well be any number of things but first you need to ascertain if its the wiring , motor or both.

The best thing you can do is remove the rubber bung on the plenum infront of the motor, let the water drain out naturally, no need for a filter.

No, don't use wd40

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OK, contact cleaner with grease?

don't be wiring things direct to anything

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I meant get a live wire and touch the contact to see whether it spins up

first check the voltages at the connections to the motor, that will tell you what you need to know.

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This sounds like a better plan than the touch test

It could well be any number of things but first you need to ascertain if its the wiring , motor or both.

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Yeah, that sounds a good plan

The best thing you can do is remove the rubber bung on the plenum infront of the motor, let the water drain out naturally, no need for a filter.

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I'm not 100% I have anything in front of the motor, that's how I can reach in and spin up the fan with my hand - there's nothing to connect the chamber to the wing vent, it's just taking the air out of that general area, but from the engine compartment... So, maybe (once I have it blowing) I need to find whatever it is that connects the two :/

HandyAndyUK said:

OK, contact cleaner with grease?
I meant get a live wire and touch the contact to see whether it spins up
This sounds like a better plan than the touch test
Yeah, that sounds a good plan

I'm not 100% I have anything in front of the motor, that's how I can reach in and spin up the fan with my hand - there's nothing to connect the chamber to the wing vent, it's just taking the air out of that general area, but from the engine compartment... So, maybe (once I have it blowing) I need to find whatever it is that connects the two :/

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I would, you are basically pulling engine fumes into the heater and then into the cabin, thats not good for you.

oilite bushes phosphor-bronze bushes light machine oil the bush absorbs some of the oil grease is a no no same with WD40 the name is a hint To linking out ,bypassing is a fire starter expensive if you the destroy the harness or the ECU in many cases
check the earth and the heater switch and motor connections,also the fuses for corrosion on contact blades .
start earth connection then check fuse connection then the switch for correct operation finally the motor connection and brushes View attachment 199198

mystery said:

oilite bushes phosphor-bronze bushes light machine oil the bush absorbs some of the oil grease is a no no same with WD40 the name is a hint To linking out ,bypassing is a fire starter expensive if you the destroy the harness or the ECU in many cases
check the earth and the heater switch and motor connections,also the fuses for corrosion on contact blades .
start earth connection then check fuse connection then the switch for correct operation finally the motor connection and brushes View attachment 199198

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Excellent wiring diagrams, but I notice the 2nd one is labelled as UP TO 1986, maybe 86 to 91 would be more accurate?
Also notice each filament on the headlamp bulbs has its own fuse?
Ps you have not water marked the first digram.

mystery said:

oilite bushes phosphor-bronze bushes light machine oil the bush absorbs some of the oil grease is a no no same with WD40 the name is a hint To linking out ,bypassing is a fire starter expensive if you the destroy the harness or the ECU in many cases
check the earth and the heater switch and motor connections,also the fuses for corrosion on contact blades .
start earth connection then check fuse connection then the switch for correct operation finally the motor connection and brushes

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Awesome diagrams,
I assume however that as mine is originally a 1985 One Ten, with a 200Tdi engine, that some of the wiring will be a hybrid of the 1985 and the 1986 onwards plans... And also that some "modifications" may have been made in the intervening years.
Did you Draw those plans, if so, what (software) did you draw them in, I'd love to construct an accurate wiring diagram of mine, and add in the bits I find along the way

good old windows paint

mystery said:

good old windows paint

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Windows Paint, and a huge amount of patience!
I'll have to investigate the wiring I have, and then get it mapped out, will make the future much easier when the inevitable issues rear their heads.

HandyAndyUK said:

Windows Paint, and a huge amount of patience!
I'll have to investigate the wiring I have, and then get it mapped out, will make the future much easier when the inevitable issues rear their heads.

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Why? It will be the same wiring in every other Land Rover of the same age, if its had a 200 put in it, it could well be using the same engine harness as original. Drawing up a wiring diagram for a vehicle while everything is in situ? No offence but that is mental.

If you have to give it an initial push to get going then it is usually the brushes are dirty or just needing changed as burnt out. You need to have a look.

Gmacz said:

If you have to give it an initial push to get going then it is usually the brushes are dirty or just needing changed as burnt out. You need to have a look.

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Irc the fan motor body is pressed heavy tin and the end caps are crimped/tabbed on, so might be hard to open/service?

lynall said:

Irc the fan motor body is pressed heavy tin and the end caps are crimped/tabbed on, so might be hard to open/service?

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You literally have to smash them open, I could be wrong, but I seem to remember the last one I took apart being brushless.