Rad Fan Problems

[dirtdog 4]

Ok..there is a test plug for the rad fans near the passenger headlight yes? I've seen pictures on other topics along with information, showing a brown 5 hole plug with 3 pins (Gtis i'm guessing)... now I've looked under my bonnet(on a STDT) and found a brown plug but it's only got 3 holes with 3 pins.. and I can't get the low OR the high speed working. So i'm thinking that either i'm using the wrong plug..or the fan motors are dead?

 

It has only run once before...made a hellish noise so I knocked the engine off. And have had a bump since where the driver side bumper bracket did enter the fan(but not break it) and puncture my rad...but I can't see this being the problem as it didn't really damage the fan at all

 

The engine doesn't run hot..only in the summer in traffic and I want to try get it sorted sooner rather than later. Has anyone changed the motors before? I'd rather swap the motors over if that's easier, rather than refitting the rad (absolute nightmare haha)

[Anthony 1,003]

Unplug the 3-pin connector from the radiator thermoswitch, and shorting two of the pins together should bring the fan on slow (running in series) and shorting the other two should bring the fan on fast (running in parallel) - from memory it's pin1 that's common, but just try the various combinations. If that works, then the thermoswitch is dead, and if it doesn't, then there's something else amiss - possibly the fans, possibly the relays, possibly the earths.

 

PS. On a diesel you'll need the ignition on for the above test, but this isn't needed on GTi's

[dirtdog 4]

Thanks Anthony. Ill give that a go and see where I am from there.

 

Didn't know I had to use the plug from the radiator. I was under the impression that the brown plug (that's just dangling away near the battery/passenger head light) was for checking the fan

[Anthony 1,003]

In theory it is (if you're using the right one) but I prefer to use the actual plug that connects to the thermoswitch.

[dirtdog 4]

In theory it is (if you're using the right one) but I prefer to use the actual plug that connects to the thermoswitch.

Just been for a poke around and turns out I was already trying the thermoswtich plug...it wasn't plugged into the top of the radiator...oops

 

Not that it would make much diffrence, because neither fans work when I bridge the terminals. So it's...earths? Or relays? Or the motors themselves?

 

I've checked the "shuntbox" (the little black box sandwiched infront of my battery and behind the slam panel?) for any blown fuses as I have heard that the fan fuses are here, not the glovebox. But there aren't any fuses in there, just relays?

[Ryan 99]

The shunt box is separate from the box with the three fan relays. It should be right next to it, just behind the headlamp.

[Anthony 1,003]

That's not the shuntbox - those (three) relays are the fan control relays.

 

The shuntbox is about a third of the size - follow the battery positive and one of the wires should connect to it.

 

Do you have a multimeter? It'll make verifying where the fault lies much easier if you do.

[dirtdog 4]

The shunt box is separate from the box with the three fan relays. It should be right next to it, just behind the headlamp.

Ok thanks ryan. I'll have to have another look

[dirtdog 4]

That's not the shuntbox - those (three) relays are the fan control relays.

 

The shuntbox is about a third of the size - follow the battery positive and one of the wires should connect to it.

 

Do you have a multimeter? It'll make verifying where the fault lies much easier if you do.

 

 

No mulitmeter I'm afraid. I'll have a ask around and see if I can borrow one.

 

I've got a box just near the windscreen with a relay or two in it.. and i've got another..four i think in the one near the slam panel

 

I'll have a search for the shuntbox later and see if my fuses have gone..fingers crossed

 

Thanks

[Anthony 1,003]

It's not the box just behind the passenger side strut top - that has the dim-dip and (where fitted) air horn relays in it

 

As Ryan said, it's normally somewhere near the slam panel or passenger headlight, but follow the battery positive cable and you'll find it - one end goes to the starter and alternator (ignore that) and the other goes to the shunt box.

[Ryan 99]

This is where is is on the GTI, the STDT might be slightly different, but it looks the same, and it's in the same area...

 

 

[dirtdog 4]

Thanks.

 

Ok the fuses aren't gone. Any suggestions?

 

Question I should really be asking now (I think) is... can I replace the motors for the fans with other ones? Say...106 or 306.. or will they not fit and force me to find 205 motors?