Fans aren't turning off

[Bug_racer]

I've got it, but not sure if taking it out will cause coolant to leak out.
Would the blown fuse have anything to do with it?
Which sensor should I replace first? And where can I get one.

Don't pull it out just check to see if there is power coming out of the switch

[stefcio007]

So, coolant is actually leaking from the sensor area, just booked it in to get it all sorted as I don't have time to do it all myself.

[The_Hawk]

Exploratory fixing on a car... that's not going to end well. I'd suggest they will remove the sensor, fix the leak and after that it's anyones guess.


To test a sensor you can either read it with a computer or a multimeter to see if it's reading correctly (and changing it's reading) as expected.

In this case, one of the other options is to plug in a spare (and known good) sensor and see what happens. Since the new sensor should be reading ambient temp the fans shouldn't come on. If they do, the problem is somewhere else.

Finding a random electrical problem is a bloody nightmare. It's a toss up between a good VAG specialist and an auto electrician who knowns VAG and it's likely to be long and expensive unless you get really lucky.

[stefcio007]

So, I was having a chat with my dad about buying a new Ford. And wouldn't you know it, the fans all work perfectly normal now!
I verified this a few times, just to be sure.
Going to buy new seals though to make sure I stop leaking, even though it's very minor.
here's hoping the issue doesn't re-appear.

[The_Hawk]

Have to wonder if it was loose wiring on one of the sensor causing the issue and all the fiddling as fixed them up!

[stefcio007]

Have to wonder if it was loose wiring on one of the sensor causing the issue and all the fiddling as fixed them up!

I think you might be right, it's gone bad again.
But I can't get any resistance from the brown sensor at all, might be on its way out? I'll be pulling them out tomorrow so that I can test them properly. Maybe the coolant has affected the wiring? Is it corrosive?

[stefcio007]

so, turns out the sensor was held in place using silicone and I also had a leak coming from the water pump.
All fixed now!

[stefcio007]

Sorry for bumping an old thread.
My "fix" for the fan issue had been to keep the 20A fan relay fuse removed because the issue eventually came back randomly.

Didn't know what the fuse was for and didn't appear to change anything when removed.
Today driving and wondering why the AC wasn't working. Turns out that fuse has to be in there otherwise it won't work.
Basically comes down to two things. AC sensor or fan relay module.

I don't mind the fan coming on during the hotter months since it "should" come on if it's hot, even if it isn't hot and it comes on, at least during summer it won't bug me when it happens.