Blower fan working on lower speeds INTERMITTENTLY?

[Kenton]

Much as the title really. I am confused as this has happened a couple of times recently. The blower fan will suddenly cut out when on anything but speed 4. When I turn it to 0 a few times, it will work fine again. Setting 4 works fine - every time. This does not sound like the resistor to me as it is intermittent. I did read some other threads saying that the plugs could be at fault and that the earth pin melts the connector. But not really too much to go on. Is this the plug on the motor, or the resistor? I will be taking it all apart as soon as I can, but wanted to see if anyone could shed a more definitive light on what this could be. The pollen filter is new, and the fan is free from any sort of build up, and generally works very well indeed. Bit of a head scratcher. I don't want to head in the wrong direction if I can help it, and just start removing everything if I can help it.
Cheers for any help guys
K

[Altransit]

Would it be likely to be the switch itself

They have been known to burn out, but failing that, the next most likely would be the connectors on the switch, and/or on the resistor

[Kenton]

Would it be likely to be the switch itself

They have been known to burn out, but failing that, the next most likely would be the connectors on the switch, and/or on the resistor

Hello Al, thanks for that. I did wonder if it could be the switch itself, but it just doesn't seem like it if you know what I mean. It never shows any sign of being dodgy normally. When this does happen, it is always speeds 1 2 and 3 that fail to work. 4 is fine. The next thing, they are all working perfectly again. I know the switch assemblys are very cheap to replace as the mk 1 for ones are the same. The connector on the resistor is my first port of call I think... When I have the dash panel off, I will have a look at what the multi meter throws up in terms of voltage. That would hopefully irradiate the switch
Cheers again m8.
K

[Altransit]

Yes, I would agree, if it's always ok on No4, I glossed over that bit on your post

Resistor or connector to, should be the culprit

[Kenton]

Yes, I would agree, if it's always ok on No4, I glossed over that bit on your post

Resistor or connector to, should be the culprit

Haha, that's ok Al. The symptoms aren't as straightforward as I would have liked to be honest. When it first happened, my first thought was the resistor. But when it started working on all speeds correctly again, it threw me. And has been fine for about three weeks - again, on all speeds, then yesterday, it happened again I will update as soon as I manage to get the time to diagnose!....
Thanks man,
K

[metalworker0]

Unless it's the bearing , number 4 I would imagine, would be no resistor ..strait through - full power.
For a few years now fans have been built with swiveling bearings, (dont know if its the case with car and van fans) they are ok until they stop swivelling...the fan rotor then touches the sides of the stator and stops turning ..would need maybe number four to overcome the jam.
if it is the swivelling bearing --which btw is meant to keep the fan centred when its working right. the cure is to lubricate the bearing until it swivels ..this usually means complete disassembly...as the swivel is usually filled with dust and no amount of external lube will free it up so that is quite loosely swivels...it has to swivel with the slightest touch when working correctly.

if this is not so with cars and vans, well sorry, you just got some good advice hopefully for "all" fans and some motors and small motors that mysteriously slow down jam and stop working ..this also goes for tumble dryer drum bearings .

all the best..mark