If your T4 cooling fan has packed up, read this, it may help

41266 Views 20 Replies 9 Participants Last post by kingsmith, Sep 18, 2009

H

Discussion Starter · Jul 25, 2009

3

I wrote this a couple of days after I picked up my van two years ago, no trouble since...

Had a little look at this at the roadside when it overheated one day, preliminary findings were that there was no power to the main lead into the thermo switch.

Studied the circuit diagram at home which looked straight forward enough but had no time to work on it.

Me and a mate had little look at it - no power in the fuse box or through the loom, but shorting out pins in the thermo switch plug we could get the low speed to run and we had a cunning bodge plan until we heard an ominous clunk and everything stopped again - big high power relay thing seemed to have died, different to the one in TC's syncro so we couldn't even try it, so home I went.

Looked at it again trying to come up with another temporary bodge... ...and I figured it out... ...and laughed :lol:

Have a look at this...

...I distincly remember TC saying to me "you won't have to worry about blowing fuses with this fix because we're tapping straight into these high power fuses here" - now look again...

...now look at this...

I found it would supply power until it got hot then curved away like the bi-metallic strip in a kettle and shut everything down until it was cold again and reset, our ominous clunk was the relays breathing their last as the power got cut again, not them sticking as we had thought.

44p each, prices may have risen since, I now keep spares in the glove box, but have never needed to change them again

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1 - 20 of 21 Posts

Tee4Ant

· #2 · Jul 25, 2009

Very good info and pics... wish i seen this last week.

My van overheated last week and baffled the fook outta me...

Didnt know what to do, thought it was gonna cost me fortune for an auto leccy...phoned matt from b.y and he pointed in the direction of this little black box, i pull the cover up and voila...It turned out it was the strip fuses as above... the 2 had blown right in the middle..

..

Cost me 2 quid for 2 fuses...

.

Loving the H2O section...

.

Ant.....................................

Paul Knight

· #3 · Jul 29, 2009

my van suffered from this problem - took me weeks to find it! good advice

andyroo82

· #4 · Aug 10, 2009

Where about's is this in the engine bay? My cooling fans aren't working so trying to narrow the search

H

Discussion Starter · #5 · Aug 10, 2009

andyroo82 said:
Where about's is this in the engine bay? My cooling fans aren't working so trying to narrow the search

Tucked behind the front panel, just above the nearside headlight. big wires going through it, in front of the battery, can't miss it

dbug

· #6 · Aug 10, 2009

i have just removed the fan flaps that are fitted behind the rad to help get more air through the rad ( and an intercooler )

they are held shut buy a heavy spring until the fans cut in which then push them open under the pressure of the fans !!

it may also explain the extreamley fast warm up time for a T4 . my fans haven't cut in since i did it and the temp holds a nice 90 deg regardless.

quick and easy mod to do....
remove front panel
drop rad forward on mounts
disconnect power to fans
remove spring thing in middle of fans
use pliers to remove each of the flaps - try not to drop any into the rad ( not major if you do just means you have to get them out )
cut the ring that held the blades and remove
refit power leads, rad and panel.

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veedweeb

· #7 · Aug 12, 2009

H said:
Awesome stuf about fuses

H... you are a feckin legend!! Mine's been overheating at motorways speeds for a while and I couldn't work out why.

Both these fuses have blown on it!

Thank you for posting this, you've saved me a world of hassle!

H

Discussion Starter · #8 · Aug 12, 2009

Don't know about leg-end, probably more like bell-end... :lol:

Happy to help

J8K VW

· #9 · Aug 12, 2009

Nice thread, I had to replace these the other day. Keeps my engine nice and cool now.

Paul Knight

· #10 · Aug 12, 2009

veedweeb said:
H... you are a feckin legend!! Mine's been overheating at motorways speeds for a while and I couldn't work out why.

Both these fuses have blown on it!

Thank you for posting this, you've saved me a world of hassle!

both?! you were lucky, dude! i think that's the entire multi-speed fan system out of action.

incidentally, these fuses are standard fitment on lots of cars, and often appear in diesels (on the glow plug circuits), so if you get stuck while on tour (as one of my buddies did in poland last week!), drop into any car spares shop or dealership and ask. he got one from a tata truck centre for pennies (and saved his head gasket, for sure!).
it took me ages to find the root of my problem when my van started cooking up, and i ended up fitting a universal relay and a switch to power 1 fan (which was more than enough to cool it on even the hottest days). but it was no substitute for the multi-relay, multi-speed, twin fan factory system. it's very clever, and i'd be wary of modifying it too much (flap removal etc). i'm not sure if the engine will warm up enough (or quick enough) in the winter with the flaps removed?

veedweeb

· #11 · Aug 13, 2009

Paul Knight said:
both?! you were lucky, dude! i think that's the entire multi-speed fan system out of action.

It's out of action for sure now.

Just been for a drive, put £75 of diesel in it

...

Got home and there's a burning smell... stopped the van to see smoke pouring out from under the bonnet. When I opened the bonnet up, the fans (both of them) were on fire!!!! Flames and everything.

The replacement fuses hadn't blown either. I don't know what rating they are, but something has clearly gone awry somewhere.

Anyway, fire's out, battery's disconnected and it's all safe. No real damage done but I'm on the hunt for a pair of new fans now.

H

Discussion Starter · #12 · Aug 13, 2009

Fuckin' 'ell

Paul Knight

· #13 · Aug 14, 2009

jesus! was there something jammed in them?!

veedweeb

· #14 · Aug 17, 2009

H said:
Fuckin' 'ell

That's all most word-for-word what I said!!!

Paul Knight said:
jesus! was there something jammed in them?!

I dunno. It was late Thursday night and I was going to drive it from Manchester to Devon for Dubs at the Beach.

I've not had chance to see what caused the problem yet. All the wiring loom to the fans has melted though. At least it explains why the two original fuses had blown.

veedweeb

· #15 · Aug 19, 2009

Just an update now.

I've just removed the fans...

Both of them are completely seized. After a lot of fiddling I managed to free them off but it's academic really - new ones have been ordered and are on their way here.

And the damage from the fire? Just the fly leads that go from the fans to the connectors at the bottom of the radiator. I consider myself very lucky indeed!!

Where did you get the fuses from? The VW van centre parts dept didn't have them even listed.

And what rating are they?

veedweeb

· #16 · Aug 27, 2009

Just thought I'd update this.

I got a pair of replacement fans from Tidy Transporters for £20 plus postage. Luckily they included the section of wiring that was damaged in the fire.

A quick trip to the main dealer armed with a part number for the fuses (thanks H) and it's all back together and working perfectly again.

For reference, the part no. for the fuses is N 0171251 and they were 54p each. I got them from a VW car main dealer (as opposed to a van main dealer)

H

Discussion Starter · #17 · Aug 27, 2009

Cool, glad it's sorted

I've never understood why the van dealers can't find that part, they have the same drawings I do and I'm just a goon off the street...

Paul Knight

· #18 · Aug 27, 2009

i think that's the same fuse/part no for some tdi golf glow plug circuits. that's possibly why the car parts dept had them listed
whatever, that's one for the glove box notebook list, for sure

H

Discussion Starter · #19 · Aug 27, 2009

Paul Knight said:
i think that's the same fuse/part no for some tdi golf glow plug circuits. that's possibly why the car parts dept had them listed
whatever, that's one for the glove box notebook list, for sure

Yeah it's common across the cars and vans since the 80's for all sorts of high power stuff - glow plugs and fans

SPANNERBOY

· #20 · Aug 28, 2009

Always carry a spare,they are pennies and could save your engine.sellotape the fuse to the inside of your manual booklet.

You may have to remove the cover on the right hand side,then they are on the inside of the slam panel,they are the same as glow plug fuses on all dieses.

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