Why does my rad fan fuse keep blowing?

[ian65]

Interesting stuff....... that's the opposite to mine...... on mine, the fan +V is wired directly to the battery via a fuse and the neg controls the fan speed.

[Lucky]

Well, I reckon I found the problem! The fan spins freely... most of the time. Then every so often it just stops, and it's quite a wrestling match to get it to turn, even by hand. I put the battery right across it straight when it locked up, and all I got was sparks, no movement at all. Until I freed it up by hand, then it would run again. And then I found out why all the manuals and stuff say to keep your fingers away from spinning fans It's OK, I managed to not get any blood on the wife's best carpet on my way to the bathroom, and my left ring finger was never my favourite one anyway

It's a bit sore now the adrenaline's worn off though



Sooooo, brand new 16" Spal one now on order. I think I've conclusively proved that every single component of the Kenlowe setup is... well... shit . Pardon my French. Still gonna re-do all the wiring anyway, partly cos I've already stripped it all out and found some bits I'm not impressed with (like, the fuse is the wrong side of the relay, and overall the wiring stretches out longer than the actual car ). Hopefully this will finally sort the bugger

[KiwiDave]

I think you've investigated the whole electric fan issue quite thoroughly now! Can you still return the kenlowe unit under warranty? (with suitably sternly worded note attached)

[Lucky]

Right, I've got a new problem now.

I've re-done the wiring, exactly as I first described it but with the suggestions in Pete's post regarding which relay terminal goes where. I've got a new fan. It all works.

BUT as soon as the negative terminal is attached to the battery, there's high-pitched whine coming from inside the cabin. Is this the coolant buzzer? On the FD all you have to do is bridge the low coolant sensor to earth to stop it. This makes no difference here. As far as I can tell, the wire from the sensor isn't broken. The whine sounds whether or not the ignition is on, literally as soon as the negative clamp is put on the battery. There's coolant right to the top of the rad.

WTF!?

[ian65]

gotta be something to do with the new fan wiring then hasn't it? I ******* hate electrical gremlins..... I still can't get my electric windows to work after 12 months

[Lucky]

I don't understand how it can sound without even having the ignition on.

Some further troubleshooting throws up these facts;

The fan works... it comes on at the preset temp and goes off perfectly happily.
The coolant level sensor seems OK; if I disconnect the wire to it, after a few seconds the "add water" light comes on the dash and it goes out if I re-connect the sensor. But the bleeping carries on regardless.

Could it be an earth point I missed re-connecting when the battery was out? Where does the coolant level sensor wire go back into the loom? Is it earthed anywhere?

Baffled

[DKWW2000]

Nik,
Disconnect the Rad sensor & Earth through a switch in cabin. You can control the Fan yourself in Traffic etc, that will work to get you to RR, perhaps we can then sort out.
It sounds like it is conflicting with low level sensor.
There are a couple other options we could discuss

[DKWW2000]

Having now had time to study the wiring diagram it looks as if (I could be wrong) that the low level sensor is just part of a much larger control unit which controls the light/buzzer & relies on the radiator/water temp & resistance via coolant Earth.

The Fan sensor operates through the water temp & there is some current interference/leakage between the two hence BUZZZZZZZZZZZZZZZZZZZZZZ

Solution 1:- Replace Rad sensor with 2 that has a inbuilt switch (type with 2 terminals) that is isolated from the radiator & is earthed direct.

Solution 2:- Manual switch as previously mentioned above.

A second opinion/conformation would be helpful.

[spirit r]

Solution 1:- Replace Rad sensor with 2 that has a inbuilt switch (type with 2 terminals) that is isolated from the radiator & is earthed direct.

Something like the inbuilt switch sensor left from the water pipe or left from the radiator cap!!

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[KiwiDave]

You could find the buzzer unit and disconnect it ... either under the dash or in behind the center console. If I recall correctly, the coolant buzzer is intermittent. If it's constant, then it's the 'headlights on' buzzer.

Is it sounding even with the ignition off?