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mjcp

Heater fan - a self resetting thermal fuse...!

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I have replaced the thermal fuse once and it has now gone again... My fan spins freely by hand, but I can hear a squeak on occasions when it starts on position 4 (the only one now working).

 

I suspect I left it on Position 2 and it got too hot while trying to start... :bonk:

 

Anyway, I did some digging and located these:

 

http://uk.rs-online.com/web/search/searchBrowseAction.html?method=getProduct&R=2047483

 

However... The highest temp they offer is 140Deg C (lower than the 184 Deg C of the original fuse) and they are rated up to 2.5A (although the data sheet says 9.6A max), far lower than the 10A of the original.

 

My question is: What is the current rating required? Does the fan draw more than 2.5A on startup or while running? (the heating fan is on a 20A fuse in the circuit board, though this is not dedicated just to the fan)

 

Assuming the 2.5A is sufficient, in the event of an overheat (140Deg C) cutout, all that would be needed to reset would be turn the power to the fan OFF and then wait/recycle the power once the temp is below 90Deg C...:cheers:

 

Any thoughts?

 

 

Marc

Edited by mjcp

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So no-one has any thoughts on this... no-one else tried it... no-one want to give guesstimate on the current draw on fan startup...?

 

No-one even going to say Good luck?

 

Oh well.. if I get time I'll pop over to RS and give it a go... and then wont tell anyone if it fixes the age old problem with simple, self resetting solution!

 

Marc

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Good luck! I can't really help you with this unfortunately, but I do empathise! The fan on my vr only works in speeds 1,2,3 and not 4, which is rather puzzling!

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Can't help with your question either mate but I'll be interested to know if it works. Good luck!

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Hmmm I did this recently and just ordered the spec stated in the Wiki guide from Maplins. (Thermal Fuse 184C RA19V £0.71 )Not sure if that's what you're looking for tho?

Edited by jamiehamy

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Hmmm I did this recently and just ordered the spec stated in the Wiki guide from Maplins. (Thermal Fuse 184C RA19V £0.71 )Not sure if that's what you're looking for tho?

 

Been there, done that, worked for about 3 weeks.... There is a definite squeak when the fan starts (position 4) when cold, so I suspect the fan is not as free running as it should be. (Hypothesis: on lower fan speeds, there is too much friction to start spinning = gets too hot and burns out the thermal fuse).

 

I bought the one resetting fuse in stock at RS Feltham today... reports to follow ;-)

 

marc

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you have aircon too, dont you Marc? If so the housing is a nightmare to manage. Spray some wd40 in the bottom end of the motor and turn it over by hand. I would look to see if you dont have a leak from the scuttle cover as this is what will affect the bearings.

If it doesnt work then you'll have to drop the motor and lube the beariings properly. Also check if there's anything snagging on the fan blades themselves, maybe some leaves on the inlet side. Let it run on 4 for a hile and see if any extra crap blows out of the vents.

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Nope, no air-con...

 

The fan came out easily for the first fuse change, I was able to spin it freely and it felt straight (eg as if the "bearings" weren't worn)... There was rust on it though so defo moister getting/gotten in at some point (Screen clears quickly, no wet foot wells etc).

 

Marc

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Hey guys, I'm not familiar with the set up in the raddos but recently had to replace a fan resistor in a Peugeot 307 which had identical symptoms to yours.

 

The symptoms we were experiencing were that it would only work on position 0 and position 4, and as it transpired the resistor was bypassed when the fans were switched to position 4. Simply replaced the resistor and it worked on all intermediate settings also. The resistor was expensive from Peugeot (came to about £50) but this was a small price to pay for the comfort of having fan control again!!

 

As I say, I'm new to the Corrado, but if they do have a variable resistor to control the fan, it may be a good call to check its condition out also.

 

Hope you get it sorted.

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Have you dismantled the fan to clean out the bushes and so on? It's really easy to to, jsut press in the rubber tabs and it all lifts out. Make sure you have disconnected the wires by popping of the resister cover.

 

I did it with mine and greased it all up, stopped the squeaking :)

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Have you dismantled the fan to clean out the bushes and so on? It's really easy to to, jsut press in the rubber tabs and it all lifts out. Make sure you have disconnected the wires by popping of the resister cover.

 

I did it with mine and greased it all up, stopped the squeaking :)

OOO i need to try this! mine squeaks like a tinny beast!

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OOO i need to try this! mine squeaks like a tinny beast!

 

I footered about for ages getting the white fan off, then realised it doesn't actually need to come off, in fact, it's easier to remove the motor with it on. It's a bit of an hand-robatic feat getting all the rubber tabs depressed in tho!

 

Very satisfying hearing it whirring quietly!

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Ditto, mines like a tortured mouse behind the dash. Seems worse on colder days. My fan doesnt work on one anymore, dont know if its related. Any particular grease to you when lubing the bearing?

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I can't remember exactly, but it was something light, not actually grease tbh. I'm sure I sprayed it all with GT85.

 

I'm sure someone will know the best stuff to use tho. I'm sure the bushes don't actually need it, but it's never done any harm to mine, or the countless model trains I used to dismantle and make run better by lubricating when I was young :)

 

I found the lower bearing/spindle bit was pretty rusty, so that got proper grease. Cotton wool buds are good for fiddly bits on the casing.

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Partial SUCCESS!

 

I replaced the recently replaced thermal fuse with the 150 Deg C Self resetting fuse from RS this morning.

 

The fan spins up on all 4 speeds, so I'm guessing the current rating is sufficient!

 

About 20 minuets later, I noticed the fan had stopped on position 2 but still worked on 4...

 

I then turned the fan OFF and left it for 20 minutes, after which time it again worked on all 4 speeds!!!

 

Next up... remove fan and grease like a stuck pig!

 

Marc

 

Arrows:

 

Big = New fuse, tucked behind terminals.

2 x small, the connectors from the fuse to the original fuse connection points. (the lower right one has 2 connections, one pinched, one soldered (you will see when you remove yours!)

 

[ATTACH=CONFIG]45050[/ATTACH]

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Well done Marc . When can you pop down to Devon to do mine????????

 

 

Sent from iPhone 4 using Tapatalk

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Hmmm...

 

So it ran on position 2 for some 20 minuets then cut out... it reset an will run for 30 -60 seconds on 2 then cutout again... BUT... It has just run for 45 minuets+ on position 1 (where lower speed should mean higher resistance = hotter) ???

 

I'll see how it runs on the trip home on position 3...

 

 

Marc

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So no-one has any thoughts on this... no-one else tried it... no-one want to give guesstimate on the current draw on fan startup...?

 

No-one even going to say Good luck?

 

Oh well.. if I get time I'll pop over to RS and give it a go... and then wont tell anyone if it fixes the age old problem with simple, self resetting solution!

 

Marc

 

Wow, you put it so respectfully, I wonder why no-one has given you a proper reply. As a newcomer, you're not going to do yourself any favours acting that way.

 

You have already said that the fuse you are looking at is 2.5A where the original is 10A. Yeah it may work at 9.6A max, but do you really want to run it on it's breaking point? You can easily calculate the power etc of the fan motor by looking at the motor itself (it's the big metal looking bit on the back with the wires :D)

 

The squeaking means that either the bearing needs more lubrication or it is on its way out.

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Wow, you put it so respectfully, I wonder why no-one has given you a proper reply. As a newcomer, you're not going to do yourself any favours acting that way.

 

You have already said that the fuse you are looking at is 2.5A where the original is 10A. Yeah it may work at 9.6A max, but do you really want to run it on it's breaking point? You can easily calculate the power etc of the fan motor by looking at the motor itself (it's the big metal looking bit on the back with the wires :D)

 

The squeaking means that either the bearing needs more lubrication or it is on its way out.

 

If you're offended, you have my apologies, it certainly wasn't the intent.

 

My first posts on this were asking some questions, politely... when no one answered, or even offered their thoughts/support, I was bit miffed... and as evidenced by the now 2 pages of responses, things just needed a nudge it would appear.

 

As for the current, I'm well aware of P=IV (with the original, the fan would need a Power of 120W or less @10A) but at the time I didn't have the dash in bits to find the fan's rating and I suspect the original is used as its "off the shelf" rather than needing to be 10A... But as there are many on here with a savant knowledge of the C and other VW matters, I thought I'd ask the question!

 

.

 

If this is a working solution to the age old problem of thermal fuses tripping on older fans, feel free not to use it!

 

Marc

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Wow, you put it so respectfully, I wonder why no-one has given you a proper reply. As a newcomer, you're not going to do yourself any favours acting that way.

I certainly wasn't offended!

 

Git

:lol:

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