Bloody low speed fan (or lack of...)

[Chr1sch]

Hi gents,

So sadly I never managed to get to a conclusion on the gti6 forum so I thought i'd try the collective genius on here to see if anyone can help...

Ever since i bought the car (almost a year now) i've had no low speed fans, at all....ever...that goes for both fans, AND high speed the drives side fan only comes on...

So i've replaced:

1) All relays
2) One fan motor (both are fine)
3) Bitron

I've checked the continuity of the wiring around the relays which seem ok, AND if i bridge (now this was a while ago) but i think it was pins 3 &5 of the one relay both fans do spin up at low speed (so they both do work....)

Its a track car and does get hot, so i've done the AC button mod and just run the one fan (a al Rallye) at high speed which works, but its a bit cack if sitting in the pits etc, she gets hot very quickly on idle, with no low speed fan ever coming on.

I'm at a total loss, any ideas/suggestions? - the only thing i havent done is the earth under the battery as its a pig to get to and not sure how both can spin up at low speed when bridged AND one at high speed if the earth was dodgy....



Cheers

Chris

[powerandtorque]

Have you checked the condition of the round multiplug where the fan loom connects?

They're prone to corrosion and can cause all manner of relay related woes.

[Chr1sch]

Yep took that off, all absolutely fine

[Niall]

Im assuming youve checked the sockets for the fan relays and change over relay? You need to have a good look at the round multi plug that plugs into the fan unit. They all corrode and can cause a fire! Also, check the bitron unit plug especially if you're missing an arch liner on that side.

Finally, what happens if you unplug the brown coolant sensor on the thermostat housing with the engine running?

[Chr1sch]

Sockets are all fine on the face of it, if I remove the plug at the thermostat the one fan comes on at high speed

[C2K]

Odd that you say you've checked it, but this normally indicates that the fan which doesn't operate at high speed is missing its 12V feed, which is likely the common 12V for series operation.

On My HDi I had this - no low speed fans at all and only the (drivers?) fan at high speed. I had a heavily corroded pin terminal in the chassis to fan loom muliplug connector. I had to splice a wire either side of that muliplug to re-route the 12V feed.