AC - radiator fan replacement

[dlysnes]

Hey!

Has anyone seen a guide for replacing / fixing the electrical radiator fan?

I have a 2002 Superb 130 TDI and the electrical fan isn't working. This results in AC tunrning on/off every 30 seconds during idling / car still. I've tested the wiring and it reads about 13V, so this leads to a faulty fan.

So, does anyone know how to remove the fan?

Thanx for any help!

Dave

[rotodiesel]

The fan is very easy to remove but a bit tight to get at. Remove the trunking from the engine air intake to the air filter box and on the fan shroud you will see a single Pozidrive or Phillips (I can't remember which) self tapping screw. It's near the top, slightly towards the outside of the car.

Remove this screw (it will be tight and rusty) and the whole fan assembly just turns out antickockwise. It's a sod to get out unless you pull the front.

Make absolutely sure of your diagnosis before you condem the fan. They spend most of their time at half speed if the aircon is on and don't wear very much. Unlike the transverse cars, the B5.5 has a properly sized speed dropping resistor on the chassis. You need to check the fan voltage under load - ie with the fan connected. The most dodgy relay will give 13V if its not supplying any current.

Double check the relay first.

rotodiesel.

[dlysnes]

Thanx rotodiesel for the quick reply!

I've spent some months diagnosing bunch of problems after the well known water leak, ripping up almost every wire under the carpet and in the door. Finally got all the interior lights, central locking and remote control working again after replacing numerous nodes...

I suspected this fan problem had something to do with the water leak, but it doesn't seem to. Maybe I should try bypassing relay and connect it directly to the battery for fan-testing?

Where is this relay located by the way? I bought some workshop software, but it doesn't include electrical diagrams...

Gotta say tha this forum really helped me with the water ingress problem. Saved me a bunch of NOK's :-)

[rotodiesel]

From memory, the relay is the big one in the fuse box near the top. You can find it by putting your hand round the relays in turn whilst turning the aircon on and off - you'll feel it operate when you get to the right one.

This is Passat info - I've not checked the Superb but it's bound to be the same. After all, they very carefully copied all the Passat faults...

rotodiesel.

[dlysnes]

The black box in the engine compartment, or among all the relays under the steering wheel inside car?

Next to the brake power in engine compartment there is a big black box containg only one fuse, one relay and an alloy box with a bunch of wiring going in/out.

Dave

[rotodiesel]

Dave, I think it's the one in the fuse box. It's bigger than most of the others and contains some electronics. If you identify this as being the cause, open it up and look for broken soldered joints where the relay itself is soldered to the PC board. Re soldering the joints often fixes it.

It's many years since I had the misfortune to work on one of these so be careful that I don't mislead you with obsolete info. Best of luck...

rotodiesel.

[Tom_vRS]

Its among the relays under the steering wheel It the top left one from memory.

FWIW, I have one here in perfect condition - I replaced mine in my old Passat and then discovered it wasn't the relay that was at fault. They are £23 from the dealers, you can have it for £10 including delivery to Norway if you like. I've checked the part numbers and know its identical.

The fan itself is quite easy to change as Rotodiesel says, but it is so much easier if you have the patience to put the lock carrier in the service position.

What is the actual fault you have? Mine turned out to be a siezed fan which then blew the fuse. Picked up a genuine replacement fan for £70 IIRC.

[dlysnes]

Hey

The fan doesn't start at all. I can spin it easily by hand. When I'm driving the AC is working like a charm, but when I've stopped the AC turns off after a couple of minutes blowing hot air, then turns on again for 30 secs and so on.

I've set the climatronic in diagnostic mode, and this seem to happen when coolant reaches certain temperature.

So, as long as the car is moving everything is OK :-)

I'll take a look at the relay in the weekend.

Thanx guys!

[Tom_vRS]

I'd look at the fuse too. Its one of the big spade fuses that you'll see near the relay.

[dlysnes]

Good point.

I'll check that too, but would the contact near the left front headlight show 13V on the multimeter if the fuse's burned?

[rotodiesel]

It would if there was no load (motor disconnected). A useful tool for this job is a digital voltmeter with a 21W stoplamp bulb wired across it.

rotodiesel.

[dlysnes]

I see. That's why I'm not an electrical engineer I guess :-)

Great advices in such short time from bith of you!

[dlysnes]

... and even not an author... bith --> both

[dlysnes]

Hello again.

I've tested with 21W lamp. Gave 13.7V and bright light :-)

Then I tested the fan bypassed directly to the battery and it didn't work. So I removed it, took it apart and saw that two of the four brushes (we call it that in norway) were worn down, positive cur. So I guess I need new fan or fan motor. I don't expect to find these brushes anywhere...

Googled VAG number 8D0 959 455R and saw a some on ebay in pricerange $70 - $150 + shipping. Do you know if any other fits?

The easiest is of course to call dealer for new fan...

Dave

Fixable?

Edited 11 July, 2008 by dlysnes
Added picture

[Tom_vRS]

eBay Motors: New Audi A4 A6 A8 VW Passat Radiator Fan Motor Assembly (item 120282056701 end time Jul-20-08 05:37:45 PDT)

[Tech1e]

Damn it I just sold a perfectly good ac fan for £20.

[dlysnes]

Hehe.

Shipping to Norway: $40 - $60

I'll look around here I guess. Thanx anyway!

[rotodiesel]

Thanks for the feedback and picture. It should not be necessary to scrap a motor for worn brushes if the commutator (segmented copper disk which the brushes run on) is in good condition.

If you go to your local auto electrical shop you can get some brushes to fit something else which are too big. File them down - carefully and solder the new brush connecting wires to the old ones.

rotodiesel.

[dlysnes]

Well... Doesn't look to bad.

Needs some cleaning I think.

Dave

[rotodiesel]

Perfect! Make a new set of brushes (I've used vacuum cleaner brushes in the past) and solder the leads together. The ends will be welded to the brush plate assembly on your motor so you need to cut them off leaving enough copper lead to solder the new ones to.

Make sure the solder does not run too far up the copper lead - otherwise it won't bend any more!

Thanks for letting us know what the fault was.

rotodiesel.

[dlysnes]

Hehe. Guess wifey need new vacuum cleaner soon :-)

Thanx for all your help! I'll post result :-)

Dave

[rotodiesel]

Dave, out of interest, how many km has your car travelled?

rotodiesel.

[dlysnes]

Hehe,

Just passed 238.000 ;-)

[rotodiesel]

Nearly 150,000 miles. Dave, I think you got your money's worth.

rotodiesel.

[dlysnes]

Yup.

Haven't had many problems with it. Only water ingress and the radiator fan.

Some flaps in the aircon canals are stuck I think (error codes), and looking forward to a nearcoming turboswitch.

I've also disababled the EGR valve. Started leaking couple of years ago, so I got the shop to rip it and fill the hole :-)

All in all a well put-together car!

Dave